BSP: Problem in F4 help

Hi All,

While displaying a custom field as an input field with F4 Help. i used the statement:

onValueHelp = ="ICWCShowF4HelpExtern(... )"

by passing the relevant values(structure-attribute name etc..) and i am able to see the F4 help as a pop up..

But the problem here is when i select an entry from the F4 list. it is not flowing into the input field!.

Any help/hint really appreciated..

Thank You,

sudeep v d.