e-mail format

[jwb666]

I'm having a bit of a problem with e-mail format checking on my form. I can check stuff like the inputed feilds that are not filled in and display an error message, so I know its the e-mail biit thas not working. The porblem is that the error message I set displays for every e-mail addressm, even if its right. I'll get the exact code i used at a later date, but here is as exact as i can get it:

$_name = "#lots of characters, in a specific order"
$_host = "#same as above"
$_end = "#letters"

if ($email !preg_match($_name"."$_host"."$_end)
{
echo("e-mail address has incorrect format...")
}

or something like that anyway. why is it not working? help == muchas appreciated!

[bastien]

here is my email checks...

if ($_POST['email']==$_POST['email2']){
    //check to see that emails are of same type as username and are the same
    //check to see if the email comforms to the email standard ([e-mail])
    $email=$_POST['email'];              //set the variable
    if ((strlen($email)>=5)&&(strlen($email)<50)){   //min length 5 and max length 50
        if (strlen(stristr($email,"www."))<=0){     //the above denies emails starts with 'www'
            if (strlen(stristr($email,"@setropets.com"))<=0){    //denies emails with endings 'setroPETS.com'
                  if (eregi("^[a-zA-Z0-9\.\_]+@[a-zA-Z0-9]+\.[a-zA-Z0-9\.]{2,4}$", $email)){

                //checks for standard email address [email][e-mail][/email], will include '.co.uk' type TLD
                   $email2=$_POST['email'];
              }else{
                   $_SESSION['errtype']=5;           //print the error message
                   $email="";                        //kill the email variable to make the user enter it again
              }
       }else{
          $_SESSION['errtype']=5;
          $email="";
      }
    }else{
       $_SESSION['errtype']=5;
        $email="";
   }
}else{
   $_SESSION['errtype']=5;
   $email="";
}
  }else{
    $_SESSION['errtype']=5;
    $email="";
  }

hth