undefined function

["Miguel Guirao" <mguirao@xxxxxxxxxxxx>]

I'm receiving this error:
 
Fatal error: Call to undefined function: mssql_connect() in 
e:\inetpub\wwwroot\sitio\TMP5w3gxy2pnf.php on line 9
 
This is line 9:    if (!( $con = mssql_connect($maquina, $usuario,
$password)))
 
$maquina = "SERVIDOR";
            $usuario = "sa";
            $password = "";
            $BDnombre = "ProyectoRMA";
            
So, basically, any ideas of the source of this error?
 
Regards,
 
Miguel Guirao
Servicios Datacard
www.SIASA.com.mx