Many thanks, it works when I deleted the space. I am a programmer and for readability I do have a tendancy to place a space after commas on parameters.

According to help: Ask>prompt,result_variable Displays a Yes, No dialog box with the specified prompt. If the user presses 'Yes', result_variable is set to 'YES', else result_variable becomes 'NO'. Ok, I must be missing something. According to help, result_variable should ALWAYS be set to something...