Getting PID of process in Shell Script

I am writing one shell script and I want to get PID of one process with name as "ABCD". What i did was :

process_id=`/bin/ps -fu $USER|grep "ABCD"|awk '{print $2}'`

This gets PID of two processes i.e. of process ABCD and the GREP command itself what if I don't want to get PID of GREP executed and I want PID only of ABCD process?

Please suggest.