Login Script Help Needed

[rajveer]

Hello Friends In Need Lil Login Validation Help
Here is My Old Code

if ($_SERVER["REQUEST_METHOD"] == "POST")
{
    $nickname = isset($_POST['nick']) ? $_POST['nick'] : NULL ;
    $password = isset($_POST['pass']) ? $_POST['pass'] : NULL ;
    
    $clean_nick = preg_replace('/[^[:alnum:]]/', '', $nickname);
    $clean_pass = preg_replace('/[^[:alnum:]]/', '', $password);
    
    if (empty($nickname) or empty($password))
    {
        $error = '<div class="error">Wrong Nickname Or Password !</div>';
    }
    else if (strlen($nickname) < 3||strlen($password) < 3)
    {
        $error = '<div class="error">Username or Password is to short, it has to be longer than 3 chars</div>';
    }
    else if (strlen($clean_nick) < 3||strlen($clean_pass) < 3)
    {
        $error = '<div class="error">Username or Password Contains special chars. Allowed chars: A-Z, a-z, 0-9, - _ @</div>';
    }
    else
    {
        /// nothing here
    }
} 

now i want to know is that is my clean_nick verify ok ???
i used this code from gumchat

 $clean_nick = preg_replace('/[^[:alnum:]]/', '', $nickname);
 $clean_pass = preg_replace('/[^[:alnum:]]/', '', $password

if (strlen($clean_nick) < 3||strlen($clean_pass) < 3)
    {
        $error = '<div class="error">Username or Password Contains special chars. Allowed chars: A-Z, a-z, 0-9, - _ @</div>';
    } 

i want to do simply is make sure username and password are only A-Z 0-9 Or _-
can anybody make change to my code it allows many chars now i want A-Z 0-9 Or _- Only


I Am Building Community Site

[spiderwebs]

Rajveer

Use this

if(preg_match("/
[^-A-Za-z0-9._ ]/", $nickname)){
// invalid character }

[rajveer]

thnx i will try this

[rajveer]

I Created This Function For Checking Please Tell If Im doing it correct

function is_alpha($data)
    {
        if (preg_match('/^([A-Za-z0-9_-])+$/i', $data))
        {
            return TRUE;
        }
        else
        {
            return FALSE;
        }
    } 

[spiderwebs]

yes its good