I am trying to connect to my mysql database through my PHP script. It gives out the error message as follows, Fatal error: Call to undefined function mysql_connect().

What would be the exact problem for this message?.

Php5-mysql package is already installed but executing phpinfo(), doesnt show up mysql information. Also, when we tried to locate mysql.so using locate command, it does not show up any results.
But actually our mysql.so is located in /usr/lib/php5/20060613+l fs . We copied the extension to /usr/lib/php5/ext/ . And we made changes in php.ini file to extensions = mysql.so , extensions_dir = /usr/lib/php5/ext . then restarted the apache2 and mysql server and ran our script. Still the same error comes.
Please help us resolve this issue at the earliest.