Problem whith mysql_connect()

When I try to connect to mysql on a linux server It gives me the following message: "Fatal error: Call to undefined function: mysql_connect() in /home/web/media/conection.inc on line 2" It seems there is a problem in the php configuration, however I am not an expert so need help to fix this. I have another server Linux where there is no problem conecting. I have checked the php.inf file in both of the servers and they are exactly the same. However when I call a page with the phpinfo() function, in the server with the mysql_connect() problem I willl not retrieve the Mysql Information that I retrieve in the correct server, that is: MySQL Support enabled Active Persistent Links 0 Active Links 0 Client API version 3.23.36 MYSQL_INCLUDE MYSQL_LFLAGS MYSQL_LIBS Directive Local Value Master Value mysql.allow_persistent On On mysql.default_host no value no value mysql.default_password no value no value mysql.default_port no value no value mysql.default_socket no value no value mysql.default_user no value no value mysql.max_links Unlimited Unlimited mysql.max_persistent Unlimited Unlimited Can anyone help me at this please???? THanks a lot Fernando