>I have a textbox on a closeable form that has code in it's lostfocus method. Is there a way to not execute the lostfocus method if the user clicks on the close button of the form?

In your LostFocus code of your TextBox, you can put this:

IF thisform.ReleaseType=1
  NODEFAULT
  RETURN
ENDIF
*
* rest of your LostFocusCode here
*