Can anyone please show me how to change a <Ext.Container> control's cls when a row is selected in a <Ext.GridPanel> ?

For example, I have a GridPanel named "GridPanel1" and a Container named "ContainerDetails".
When a user selects a row in GridPanel1, I want to change the selected row's background color to a different color,
Also, at the same time change the "ContainerDetails" background color to the same background color as the selected row
in "GridPanel1". In my case, the CSS I want the selected row and ContainerDetails to get changed to is "highlightDetails".

Can anyone please show me how to accomplish this effect?
Any help is greatly appreciated! Many thanks in advance!

Below is my code for the "GridPanel1" control:

<ext:GridPanel ID="GridPanel1" runat="server" Title="Runs" Margins="0 0 0 0" Icon="ScriptGo"
                                Height="500" Width="479" BodyCssClass="x-grid3-row-selected x-grid-group-title"
                                StripeRows="true" TrackMouseOver="true" Frame="false" Border="false" Padding="0"
<ColumnModel runat="server">
                                        <ext:DateColumn DataIndex="WrapStartDate" Header="Wrap<br/> ST" Format="M/dd/yy"
                                            Width="60" Align="Center" />
                                        <ext:Column DataIndex="DoughName" Header="Dough Name" Width="132" Align="Center" />
                                        <ext:DateColumn DataIndex="WrapStartDate" Header="Wrap<br/> ST" Format="H:mm" Width="60"
                                            Align="Center" />

                                    <ext:RowSelectionModel ID="RowSelectionModel1" runat="server" SingleSelect="true">
                                            <RowSelect OnEvent="RowSelect" Buffer="100">
                                                <EventMask ShowMask="true" Target="CustomTarget" CustomTarget="#{PanelRuns}" />
                                                    <ext:Parameter Name="RunId" Value="record.data.RunId" Mode="Raw" />
My code for the "ContainerRunDetails" control:
<ext:Container runat="server" ID="ContainerDetails" Cls="highlightDetails" Width="550"
                                        DefaultAnchor="100%" Split="false">
                                            <ext:Panel ID="Panel2" runat="server" Title="Run Details" Icon="PageWhitePasteTable"
                                                Cls="highlightDetails" Frame="false" Border="false" Width="550" ButtonAlign="Center">