In LEADS, i'd like to have a pop-up window appear requesting input for a value on a pick list field if a boolean field is selected/true.

How do I do this?

The boolean field is called "Made Contact with Seller" (when checked)

Picklist field is "Plan for the property". Values could be A, B, C, or D.

If this requires a function please spell it all out for me. I have no clue how to write one.