Syntax formula for Not blank/empty

Question

Hi All 
 I am hoping this is a simple one to solve 
 We have a number of requirements to display/require fields if another field is not empty 
 
 Syntax below gets accepted but is never true 
 
 What is the correct reference to use? 
 
 I have tried 
 not(equal($pr_date_proofs_rejected, " ")) 
 not(equal($pr_date_proofs_rejected, "blank")) 
 not(equal($pr_date_proofs_rejected, "null"))

Taufique Ahmed · Accepted Answer

Hi Taufique Ahmed , 
 Your first formula is close. It's looking for a field where a space character is stored which is technically not empty. Instead, the formula should be: 
 not(
 equal(
 $pr_date_proofs_rejected, 
 ""
 )
) 
 Chris