The value of the control is always empty if this control contains in the tab panel

[AlexMaslakov]

I've a tab panel.

tab = tabPanel.add({
                    id: id,
                    title: title,
                    closable: true,
                    autoLoad: {
                        showMask: true,
                        url: url,
                        mode: "iframe",
                        maskMsg: "Loading... " + title + "..."
                    }
                });

It contains some controls and the button.

 <ext:TextField ID="test1" runat="server">
    </ext:TextField>

<ext:Button runat="server" ID="SubmitTxt" Text="Save">
    <DirectEvents>
        <Click OnEvent="SubmitBtnClick">
            <EventMask ShowMask="true"></EventMask>
</Click>
    </DirectEvents>
</ext:Button>

The property Text of test1 is always empty.

 protected void SubmitBtnClick(object sender, DirectEventArgs e) {
var a  = test1.Text; //a == string.Empty
}

Why? How to fix it?

[geoffrey.mcgill]

Please ensure you have those Components configured inside a <form runat="server"> Control.

[AlexMaslakov]

There is here

<ext:TextField runat="server" FieldLabel="LastName" ID="LastNameTxt" />
<ext:TextField runat="server" FieldLabel="FirstName" ID="FirstNameTxt" />