To remove (ie, delete) a control from your window, first select the desired control. Then, select Programmer Center's Edit -> Delete menu command (or press any keyboard shortcut you have assigned to it, typically the Delete key).

If you select several controls simultaneously, then they will all be removed.

Note: Programmer Center also can cut the selected controls to the clipboard, in preparation of pasting them into some other Window Layout script's window. Use the Edit -> Cut menu command to remove the selected controls and put them in the clipboard.

As an experiment, select all of the controls in your window, and remove them, so that your "List of Names" window is empty (like how it was when first created).