PHP and MSSQL7

Hi Does Any one knows why connection to MSSQL 7.0 from a PHP version 4.0 cannot be established??? all i want is to establisha connnection and i use the required function but i get the message : undefined function.... i have already check the php.ini file for the dll extension and also put it in the right path. NO HELP Pleasegive me some advise.. im runing PHP on Windows NT Server which is also the MSSQL Server 7 Machine! Thanks a lot moshe Bar-Oz