Answer : I got this info from harrytse. I just copy and paste.

You can check your System ID, but doing the following:
From the idle screen: (assuming you haven't changed your security code)

*3001#12345#

Select NAM1
Scroll to Home System ID. This is your System ID.

You'll also need the country and provider code
for the provider codes are:
Rogers AT&T (Canada): 2050
AT&T (United States): 2049

The Country Codes are:
Canada: 302
United States: 310

More details instructions below:
http://www.cellphoneuser.com/tricks/alpha.asp

Note Once you're inside the *3001 menu there is no back button, you'll have to turn off the phone and turn it back on again.

lates
Harry
"Well y'know sorry but screw that."