Finding files older than 2 hours

I want to write a sh script that will find files older than 2 hours and tar them. I've had a look at the find man page but can't see how to do it by hours.

Help please.

Thanx

Using the "touch" command, create a file with an mtime of two hours ago. The use "find" to produce a list of files older than that file. You will be using the -newer function of "find" together with ! to accomplish this.