You want the user to be able to enter a value into the Group field only when option 4 is selected in the Group drop-down, right? If I've understood you correctly there are a number of ways to achieve what you want:
Only make the group field visible when option 4 is selected. This is generally considered bad practice for UI design - users get confused when fields appear and disappear.
Only enable the group field when option 4 is selected (see code example below)
I hope you find this useful.
[ August 29, 2004: Message edited by: Julian Kennedy ]
[ August 29, 2004: Message edited by: Julian Kennedy ] [ August 29, 2004: Message edited by: Julian Kennedy ]