i need help please

I’m writing the following piece of code to get some information from an SQL Server database….
” . $numRows . ” Row” . ($numRows == 1 ? “” : “s”) . ” Returned

“;

//close the connection
mssql_close($dbhandle);
?>

but when i try to preform this page i get the following error…

Fatal error: Call to undefined function mssql_connect() in C:\AppServ\www\conn.php on line 8

can anyone suggest a solution for this error….