[scottyishere]

Does the table USERS exist? Does the variable USERNAME in table USERS exist?

pawn Код:

CheckAccountExists(account[])
{
    new string[128];
    format(string, sizeof(string), "SELECT * FROM `users` WHERE `username`= '%s'", account); 
    new q = mysql_query(string);
    if(!q) return printf("Query did not work. %d",mysql_errno());
        mysql_store_result();

    new value;
    value = mysql_num_rows(Handle);
    mysql_free_result(Handle);
    return value;
}

Try this. Check console and tell me if any error popped up.