[1337connor]

format(string1,sizeof(string1),"SELECT * FROM `users` WHERE `username`='%s' AND `password`='%s'",NameOf(playerid),password);
(Using Stricken Kids)

[Pghpunkid]

Perhaps try escaping the strings? (mysql_real_escape_string)

[DRIFT_HUNTER]

Let me guess....your server crash when you call that function....If so than your mysql server is not running or you didnt connect to mysql server