connection to a mssql server with php

[wxdqz]

Hello

my problem: i will connect to a mssql server with php - my code :
<?
$h = "server adr";
$u = "user";
$p = "passw";
$b = "db";

$connexion = mssql_connect("$h", "$u", "$p");
mssql_select_db($b);
$sql = "select * from test";
$result = mssql_query($sql_temp);
mssql_close($connexion);
?>

that the answer

Fatal error: Call to undefined function: mssql_connect() in ..mssql.php on line 7

whats the problem?????? please help me

thanks luttman