Help with validating username

[cordoprod]

Hello!

I develope a community system and I wonder which regex I should use.

 

I only want the letters [a-z] and the numbers [0-9].

Not spaces and stuff like that..

[pocobueno1388]

<?php

if (ereg("[^A-Za-z0-9]", $string)) {
   echo "Error: String can only contain letters and numbers!";
}

?>

[woobarb]

'm assuming you wanting to match?

$res = preg_match("/^[0-9a-z]$/", $s);

 

you might want to make it case insensitive also...

 

 

 

 

oh, hi pocobueno1388....

[cordoprod]

No, now it has to contain numbers, right?

It shouldn't need numbers, but only numbers 0-9 and characters a-z is allowed.

[cordoprod]

Warning: preg_match() [function.preg-match]: Delimiter must not be alphanumeric or backslash in /customers/cordoproduction.com/cordoproduction.com/httpd.www/travek/travek.php on line 28

 

I get that error... Here's my code:

function IsUsername($username) {

$regex = preg_match("/^[0-9a-z]$/", $s);

 

if ( preg_match($regex, $username )) {

 

return true;

 

}

 

else {

 

return false;

 

}

}