WinNT+Apache+PHP4 can't connect ODBC!!!

I have Win NT4.0/SP3 with OmniHttpd as my Web Server for S/W dev. project. It's about Web-Base MS Access Database with ODBC and it's run properly. Recently I decided to use Apache instead. So I remove Omni and install Apache instead, and then PHP. After that I move my program to Apache folder and run. I found it's can't connect to odbc from "odbc_connect", the error is about this Warning: SQL error: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified, SQL state IM002 in SQLConnect in c:\program files\apache group\apache\htdocs\test\odbc.php on line 6 So I decide to install Omni and shutdown Apache Service. It's work!!! ODBC is all right. But when I had shutdown Omni and start Apache service, It's doesn't. Why???? Help meeee!!! As soon as possible, Thanks.