Hello,
I have been trying to make design work but i havent been able to do what i want or at least make it work the way i want, i have done my search before making this post. I have done every possible combination i could came with before creating this post, i really need help to.
Here are my searches for those who dont believe me, these are just a few of the ones i searched:
1. http://forums.ext.net/showthread.php...ght=masterpage
2.http://forums.ext.net/showthread.php...ght=masterpage
3.http://forums.ext.net/showthread.php...ght=masterpage
4.http://forums.ext.net/showthread.php...ght=masterpage
5. http://forums.ext.net/showthread.php...anel+fitlayout

Back to my problem heres my design:
MASTER
<body>
    <form id="form1" runat="server">
    <ext:ScriptManager ID="smMaster" runat="server" Locale="es-do">
    </ext:ScriptManager>
    <ext:ViewPort ID="vpMaster" runat="server">
        <Body>
            <ext:BorderLayout ID="BorderLayout1" runat="server">
                <North>
                    <ext:Panel ID="Panel1" runat="server" Height="100">
                        <Body>
                            <asp:ContentPlaceHolder ID="NorthRegion" runat="server">
                            </asp:ContentPlaceHolder>
                        </Body>
                    </ext:Panel>
                </North>
                <Center>
                    <ext:Panel ID="pnCenter" runat="server">
                        <Body>
                            <asp:ContentPlaceHolder ID="CenterRegion" runat="server">
                            </asp:ContentPlaceHolder>
                        </Body>
                    </ext:Panel>
                </Center>
            </ext:BorderLayout>
        </Body>
    </ext:ViewPort>
    </form>
</body>
CHILD(CONTROL PANEL) ASPX
<asp:Content ID="Content1" ContentPlaceHolderID="NorthRegion" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="CenterRegion" runat="server">
        <ext:Panel ID="pnPrincipal" runat="server" AutoWidth="true" Height="600" Frame="true">
            <TopBar>
                <ext:Toolbar ID="tbMenuAsalariados" runat="server" Flat="true">
                    <Items>
                        <ext:ToolbarButton ID="1" runat="server" Icon="BulletCross" Text="1.L"
                            ToggleGroup="Menu" EnableToggle="true">
                            <AjaxEvents>
                                <Click OnEvent="1_Click">
                                    <EventMask ShowMask="true" MinDelay="500" Msg="LOAD..." />
                                </Click>
                            </AjaxEvents>
                        </ext:ToolbarButton>
                        <ext:ToolbarSeparator />
                        <ext:ToolbarButton ID="2" runat="server" Icon="BulletCross" Text="2. S"
                            ToggleGroup="Menu" EnableToggle="true">
                            <AjaxEvents>
                                <Click OnEvent="2_Click">
                                    <EventMask ShowMask="true" MinDelay="500" Msg="LOAD..." />
                                </Click>
                            </AjaxEvents>
                        </ext:ToolbarButton>
                        <ext:ToolbarSeparator />
                        <ext:ToolbarButton ID="3" runat="server" Icon="BulletCross" Text="3. A"
                            ToggleGroup="Menu" EnableToggle="true">
                            <AjaxEvents>
                                <Click OnEvent="3_Click">
                                    <EventMask ShowMask="true" MinDelay="500" Msg="LOAD..." />
                                </Click>
                            </AjaxEvents>
                        </ext:ToolbarButton>
                        <ext:ToolbarSeparator />
                        <ext:ToolbarButton ID="4" runat="server" Icon="BulletCross" Text="4. G"
                            ToggleGroup="Menu" EnableToggle="true">
                            <AjaxEvents>
                                <Click OnEvent="4_Click">
                                    <EventMask ShowMask="true" MinDelay="500" Msg="LOAD..." />
                                </Click>
                            </AjaxEvents>
                        </ext:ToolbarButton>
                        <ext:ToolbarButton ID="5" runat="server" Icon="BulletCross" Text="5. D"
                            ToggleGroup="Menu" EnableToggle="true">
                            <AjaxEvents>
                                <Click OnEvent="5_Click">
                                    <EventMask ShowMask="true" MinDelay="500" Msg="LOAD..." />
                                </Click>
                            </AjaxEvents>
                        </ext:ToolbarButton>
                    </Items>
                </ext:Toolbar>
            </TopBar>
            <Body>
            </Body>
        </ext:Panel>
</asp:Content>
CHILD(CONTROL PANEL) CODE
 Protected Sub 1_Click(ByVal sender As Object, ByVal e As AjaxEventArgs)
        pnPrincipal.AutoLoad.MaskMsg = "LOAD..."
        pnPrincipal.AutoLoad.Url = "A.aspx"
        pnPrincipal.AutoLoad.Mode = LoadMode.IFrame
        pnPrincipal.AutoLoad.NoCache = True
        pnPrincipal.LoadContent()
    End Sub
    Protected Sub 2_Click(ByVal sender As Object, ByVal e As AjaxEventArgs)
        pnPrincipal.AutoLoad.MaskMsg = "Cargando..."
        pnPrincipal.AutoLoad.Url = "B.aspx"
        pnPrincipal.AutoLoad.Mode = LoadMode.IFrame
        pnPrincipal.AutoLoad.NoCache = True
        pnPrincipal.LoadContent()
    End Sub
    Protected Sub 3_Click(ByVal sender As Object, ByVal e As AjaxEventArgs)
        pnPrincipal.AutoLoad.MaskMsg = "Cargando..."
        pnPrincipal.AutoLoad.Url = "C.aspx"
        pnPrincipal.AutoLoad.Mode = LoadMode.IFrame
        pnPrincipal.AutoLoad.NoCache = True
        pnPrincipal.LoadContent()
    End Sub
    Protected Sub 4_Click(ByVal sender As Object, ByVal e As AjaxEventArgs)
        pnPrincipal.AutoLoad.MaskMsg = "Cargando..."
        pnPrincipal.AutoLoad.Url = "D.aspx"
        pnPrincipal.AutoLoad.Mode = LoadMode.IFrame
        pnPrincipal.AutoLoad.NoCache = True
        pnPrincipal.LoadContent()
    End Sub

    Protected Sub 5_Click(ByVal sender As Object, ByVal e As AjaxEventArgs)
        pnPrincipal.AutoLoad.MaskMsg = "Cargando..."
        pnPrincipal.AutoLoad.Url = "E.aspx"
        pnPrincipal.AutoLoad.Mode = LoadMode.IFrame
        pnPrincipal.AutoLoad.NoCache = True
        pnPrincipal.LoadContent()
    End Sub
This one Fits OK no problem
CHILD-PAGE(CALLED FROM CONTROL PANEL) ASPX
<asp:Content ID="Content1" ContentPlaceHolderID="NorthRegion" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="CenterRegion" runat="server">
    <ext:Spotlight ID="spotLey" runat="server" Easing="EaseOut" Duration="0.3" />
    <ext:Panel ID="pnl1" runat="server" Title="1" BodyStyle="padding:15px;">
        <Body>
            <ext:Label ID="lbl1" runat="server" Height="40">
            </ext:Label>
        </Body>
    </ext:Panel>

    <ext:FitLayout ID="FitLayout2" runat="server">
    <ext:Panel ID="pn1r" runat="server" Border="false" BodyStyle="padding:15px;">
        <Body>
            <ext:Checkbox ID="chkAcept" runat="server" BoxLabel="Acept">
            </ext:Checkbox>
            <ext:Button ID="btnAceptr" runat="server" Text="Acept">
                <AjaxEvents>
                    <Click OnEvent="btn1_Click" Before="Ext.Msg.wait('Acepting...', 'Acepting');"
                        Failure="Ext.Msg.show({ 
                                title   : 'Error', 
                                msg     : 'Error Acepting', 
                                minWidth: 200, 
                                modal   : true, 
                                icon    : Ext.Msg.ERROR, 
                                buttons : Ext.Msg.OK 
                            });">
                    </Click>
                </AjaxEvents>
            </ext:Button>
        </Body>
    </ext:Panel>
    </ext:FitLayout>
</asp:Content>
Here Comes my problem
CHILD-PAGE(CALLED FROM CONTROL PANEL) ASPX
<asp:Content ID="Content1" ContentPlaceHolderID="NorthRegion" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="CenterRegion" runat="server">
    <ext:ScriptManagerProxy ID="smp2" runat="server" AjaxMethodNamespace="2">
    </ext:ScriptManagerProxy>
    <ext:Store ID="st2" runat="server" OnRefreshData="st2_Refresh">
        <Reader>
            <ext:JsonReader>
                <Fields>
                    <ext:RecordField Name="no2" />
                    <ext:RecordField Name="fec2" Type="Date" />
                    <ext:RecordField Name="ced2" Type="String" />
                    <ext:RecordField Name="nom2" Type="String" />
                    <ext:RecordField Name="pri2" Type="String" />
                    <ext:RecordField Name="seg2" Type="String" />
                    <ext:RecordField Name="rel2" />
                </Fields>
            </ext:JsonReader>
        </Reader>
    </ext:Store>
    <ext:Spotlight ID="spot2" runat="server" Easing="EaseOut" Duration="0.3">
    </ext:Spotlight>
    <ext:FitLayout ID="FitLayout1" runat="server">
        <ext:Panel ID="Panel1" runat="server">
            <Body>
              <ext:GridPanel ID="gp2" runat="server" StoreID="st2" StripeRows="true"
            Title="Dep2" TrackMouseOver="true" AutoWidth="true" Height="300">
            <ColumnModel ID="ColumnModel1" runat="server">
                <Columns>
                    <ext:Column DataIndex="no2" Hidden="true" MenuDisabled="true" />
                    <ext:Column Header="FEC2" Width="110" DataIndex="fec2" MenuDisabled="true">
                        <Renderer Fn="Ext.util.Format.dateRenderer('d/m/Y')" />
                    </ext:Column>
                    <ext:Column Header="CED2" Width="80" DataIndex="ced2" MenuDisabled="true" />
                    <ext:Column Header="NOM2" Width="140" DataIndex="nom2" MenuDisabled="true" />
                    <ext:Column Header="PRI2" Width="140" DataIndex="pri2" MenuDisabled="true" />
                    <ext:Column Header="SEG2" Width="140" DataIndex="seg2" MenuDisabled="true" />
                    <ext:Column Header="REL2 Width="80" DataIndex="rel2" MenuDisabled="true">
                    </ext:Column>
                    <ext:CommandColumn Width="30">
                        <Commands>
                            <ext:GridCommand Icon="BulletCross" CommandName="del" StandOut="true">
                                <ToolTip Text="delete" />
                            </ext:GridCommand>
                        </Commands>
                    </ext:CommandColumn>
                </Columns>
            </ColumnModel>
            <SelectionModel>
                <ext:RowSelectionModel ID="RowSelectionModel1" runat="server" SingleSelect="true">
                </ext:RowSelectionModel>
            </SelectionModel>
            <LoadMask ShowMask="true" Msg="LOAD..." />
            <BottomBar>
                <ext:PagingToolbar ID="PagingToolBar1" runat="server" PageSize="10" DisplayInfo="true"
                    DisplayMsg="List2 {0} - {1} OF {2}" EmptyMsg="<b>NONE</b>" />
            </BottomBar>
        </ext:GridPanel>
          <ext:FormPanel ID="frmpn2" runat="server" Title="Agr2"
        BodyStyle="padding:5px;" ButtonAlign="Right" Height="300" LabelWidth="150" MonitorPoll="500"
        MonitorValid="true">
        <Body>
            <ext:FormLayout ID="FormLayout1" runat="server">
                <ext:Anchor Horizontal="30%">
                    <ext:DateField ID="dff2" runat="server" FieldLabel="Fec2"
                        AllowBlank="false"  ReadOnly="true">
                    </ext:DateField>
                </ext:Anchor>
                <ext:Anchor Horizontal="30%">
                    <ext:TextField ID="tfced2" runat="server" FieldLabel="Ced2" AllowBlank="true">
                    </ext:TextField>
                </ext:Anchor>
                <ext:Anchor Horizontal="40%">
                    <ext:TextField ID="tfnom2" runat="server" FieldLabel="Nom2" AllowBlank="false" />
                </ext:Anchor>
                <ext:Anchor Horizontal="40%">
                    <ext:TextField ID="tfpri2" runat="server" FieldLabel="Pri2"/>
                </ext:Anchor>
                <ext:Anchor Horizontal="40%">
                    <ext:TextField ID="tfseg2" runat="server" FieldLabel="Seg2"/>
                </ext:Anchor>
                <ext:Anchor Horizontal="35%">
                    <ext:ComboBox ID="cbrel2" runat="server" Editable="false" Mode="Local" ForceSelection="true"
                        SelectOnFocus="true" FieldLabel="Rel2">
                        <Items>
                            <ext:ListItem Text="Hi2" Value="0" />
                            <ext:ListItem Text="Con2" Value="1" />
                        </Items>
                    </ext:ComboBox>
                </ext:Anchor>
            </ext:FormLayout>
        </Body>
        <Buttons>
            <ext:Button ID="btnSal2" runat="server" Text="Save">
            </ext:Button>
            <ext:Button ID="btnLim2r" runat="server" Text="Lim2">
            </ext:Button>
        </Buttons>
    </ext:FormPanel>
            </Body>
        </ext:Panel>
    </ext:FitLayout>
</asp:Content>
NOTE:
if theres a name error or something in this code its just for demostration, my problem is on design.


Thanks in ADVANCE.