In that case - please have a read through my Exchange 2003 / Activesync article, check your pre-requisites, check your IIS settings, run the test on the test site and folow the solutions for any errors you see on the test site.
If you get stuck, please let me know.
http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/A_1798-Exchange-2003-Activesync-Connection-Problems-FAQ.html