I'm using the following formula to lookup up my employees based on their ID#
and return the value in column 2 where a match is found. How do I sum up
these matches if the employee number appears more than once?

=VLOOKUP(X2,'LaborDetail'!P2:Q1000,2,FALSE)

X2 = Employee ID #
Column P = Employee ID #
Column Q = Hours worked

I want to sum up all data in column Q where the employee ID matches.