How can i hide a list box, correctly?

In my game i currently use:

Set X to Window.X-(Items.Width)-10 (to hide the list boxes)

Set X Window.ClientX+24   (to reposition the list boxes)

This WORKS fine.....but if i want to drag the game window to another position, the listboxes reappear on the left edge and move across the screen as i am dragging the window?

I have the game window set to position (0,0) on start of layout.

my game is 800x600

my display is 1024x768

Anybody know why. <img src="smileys/smiley5.gif" border="0" align="middle" />

The listbox's position is already relative to the window. The "Window.X" is not needed.

To hide or move off the visible window:

-> ListBox: Set X to 0-ListBox.Width

To show:

-> ListBox: Set X to 24

Thanks a lot Rojohound.