You can use New Window to create your own custom dialog for this and then you no longer are limited to three buttons, nor will only the first button commit the data entered. You can also now format your fields with value lists if that is helpful.
On the downside, the script gets more complicated, and the new window will have controls in it that a real dialog does not.
The Known Bugs List database uses New Window as a dialog in several areas. You can download this file and take a look at how it does it. These scripts adjust for window sizing issues if the file is opened on a windows machine. They also adjust their sizes if a windows users selects "enlarge window contents to improve readability" and pauses inside an infinite loop to make the window "modal" (User must close pop up window before returning to main window.).
Caution: These scripts use the Allow User Abort step to keep the user from canceling the paused script. Unless the buttons/scripts that close this window include Halt Script to halt the original script, they will trap you in a loop that you cannot get out of except by using either the script debugger (fileMaker Advanced only) or by force quitting FileMaker. It's a good idea to leave this step out during testing and then to add it only after you have everything else working like you want.
Thanks for the reply, Phil "...nor will only the first button commit the data entered" - are you saying that it is a 'feature' that only the default button accepts any user input? I find that really weird. I'm happy with the standard dialogue as is, if only it allowed the user-entered data to be picked up no matter which button was pressed.
Yes, that's how FileMaker designed it to work. I have no idea why they did, but that's why I'm recommending an alternative approach that does not have this limitation.
Before writing the reply, "Well, I'd call it a bug, and at least they might highlight it in the documentation" I thought I'd better check, and unfortunately they do. The help page for custom dialog says:"Button 1, the default or rightmost button, is the only button that will write information from the input fields to a file."
Thanks for clearing that one up for me.