How To Display Processes By A User

i want to know how do i display all the current running processes running by a particular user. for example, i have a web server, and i know the user is apache, i am troubleshooting some errors i am getting and would like to know which process are being running by apache user, can you help

PID TTY          TIME CMD
17989 ?        00:00:00 httpd
17990 ?        00:00:00 httpd
17992 ?        00:00:00 httpd
17994 ?        00:00:00 httpd
17996 ?        00:00:00 httpd
17997 ?        00:00:00 httpd
17999 ?        00:00:00 httpd
18001 ?        00:00:00 httpd