Warning: mysql_num_rows()

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in C:\wamp\www\VC\index.php on line 2786

Kode:

// Forbinder, vælger database
$link = mysql_connect("localhost", "root", "rm1023m") or die(mysql_error());
mysql_select_db("amxmodx") or die();

$query1 = mysql_query("SELECT * FROM admins WHERE steamid = '$_POST[steamid]'");
$number = mysql_num_rows($query1);
if($number == "0") {

mysql_query("INSERT into admins2 (r, auth) VALUES ('r', '$_POST[steamid]')") or die(mysql_error());
mysql_query("INSERT into admins (access, auth) VALUES ('r', '$_POST[steamid]')") or die(mysql_error());

}else{
}

// Luk forbindelsen
mysql_close($link);


Nogen der kan hjælpe?