Syntax Error (Improperly Terminated String ') 72 95

Hi All

I am trying to make a dynamic field based on 2 criteria, 

1 - related record, assigned to name or id = xyz

AND

2 - current record, dropdown = xyz

for example

Contact related assigned_user = id = xyz AND category = Customer

= show field

I can get them to work separately, but get an error when trying to include AND

equal: Syntax Error (Improperly Terminated String ')and(equal($pr_category')72 95