Problem with Z-index of the controls in WIXUI(Problem of overlapping)

I am trying to design a dialog box for License aggrement and other dialog boxes.

Now if I set a image(.jpg/.bmp) in background of my dialog box then the checkbox will get disappear,and it is not visible until I hover the mouse over it. And the same problem appears with a pushbutton.

*) I first thought it could be becaus开发者_如何学Goe of the large size of the image but I also tried with smaller sized images and the problem existed with them too.

*) I also tried with changing the z-index of the controls but this still did not solve my problem.

Where is the problem?. Where am I going wrong?

Have a look at the dialogs included in the UI extension, you should be able to examine similar dialogs and work backwards to figure out what's going on. There's a background bitmap on the welcome dialog for example.

http://wix.cvs.sourceforge.net/viewvc/wix/wix/src/ext/UIExtension/wixlib/

Edit: In response to the comment about the Office 2007 installation experience, Office uses an external UI, not the built in stuff that Windows Installer provides. The setup is in WiX, but the UI isn't - there's more than 20 MSI files on the Office 2007 Ultimate disk, the external UI hides all of this from you to make it appear as a single installation package when in reality it's actually a whole lot more complicated.

Edit 2: See http://blogs.msdn.com/windows_installer_team/archive/2005/07/23/442584.aspx for a good starting point on implementing non-native Windows Installer UI

I tried adding TabSkip attribute and now the checkbox is above the bitmap.

<Control Id="Image" Type="Bitmap" TabSkip="no" X="0" Y="0" Width="374" Height="234" Text="BitmapFile" />