This link talks enabling, diabling, Hiding and Displaying the button based on a dropdown value. In mycase I have to Display or Hide based on Lookup Value.
The problem I can only have a <ValueRule> but the value rule requires value represented in string. SO how can I tell in value rule to check for Null on a lookup.
My Scenario Ex.
Contact ID LookUp is empty then dont show the button
Contact ID LookUp has a value then Show the button.