I am working with EXECSCRIPT for a long time now and it is a really cool function.

I saw this on a session at german DEVCON some years ago, on how to change your app at runtime via hooks within your inputfields (textbox, editbox, combobox etc.)

However, you have to take care that there is no referencing to your current form with THISFORM or something alike. You will have to use an object reference to your forms. So weather you call your forms via 'DO FORM frmMyForm NAME ofrmMyForm' or you instanciate your form with 'ofrmMyForm = CREATEOBJ([cfrmMyForm])', take care, that there is a reference to your form available.