preg_match or ereg PROBLEMS NEED HELP!!

$usri = "Invalid Characters!"
$nopreg = "(\!\@\#\$\%\^\&\*\(\)\+\=\[\]\{\}\"\'\?\/\\\|\,\.\<\>\`\~\:\;)";
                          echo stripslashes($nopreg); 
                          if(isset($_POST['register'])){
                              if(!ereg("/$nopreg/", $_POST['username-reg'])){
                        
                              ?>
                              <span class="error">
                              <? echo $usri;?>
                              </span>
                              <?    
                              }

PHP:

This is the code, SOME REASON ITS NOT FILTERING THESE CHARACTERS!!..


Someone please, help me here.

 

did u chk this link: http://php.net/manual/en/function.ereg.php
if not hav a look plz

 

PROBLEM FIXED!!!

I just need to have double brackets like....

if(!ereg("/^([a-zA-Z0-9_])+$/"){

}

PHP:

So the fixed version looks like

$usri = "Invalid Characters!"
$nopreg = "([\!\@\#\$\%\^\&\*\(\)\+\=\[\]\{\}\"\'\?\/\\\|\,\.\<\>\`\~\:\;])";
                          echo stripslashes($nopreg); 
                          if(isset($_POST['register'])){
                              if(ereg("/^$nopreg+$/", $_POST['username-reg'])){
                        
                              ?>
                              <span class="error">
                              <? echo $usri;?>
                              </span>
                              <?    
                              }

PHP:

Which can be simplified to

$usri = "Invalid Characters!";
$username = $_POST['username_reg'];
$nopreg = "/^([a-zA-Z0-9_])+$"; 
                          if(isset($_POST['register'])){
                              if(!ereg($nopreg, $_POST['username-reg'])){
                        
                              ?>
                              <span class="error">
                              <? echo $usri;?>
                              </span>
                              <?    
                              }

PHP: