invalid email? please check over basic script

I don't know why, but whenever I enter an email it keeps coming up as invalid! Can someone help me figure out why it's coming out as invalid? also, is there a way to debug this, so I will know how in the future? Thanks

<?php

    // Function used to check e-mail syntax
    function validateEmail($email)

    {
       // Create the e-mail validation regular expression
       $regexp = "^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)
                  (\.[a-z0-9-]+)*(\.[a-z]{2,6})$";

       // Validate the syntax
       if (eregi($regexp, $email)) return 1;
           else return 0;
    }

    // Has the form been submitted?
    if (isset($_POST['submit']))
    {

        $name = htmlentities($_POST['name']);
        $email = htmlentities($_POST['email']);

        printf("Hi %s<br />", $name);

        if (validateEmail($email))
            printf("The address %s is valid!", $email);
        else
            printf("The address <strong>%s</strong> is invalid!", $email);
    }
?>

<form action="subscribe.php" method="post">
   <p>
      Name:<br />
      <input type="text" id="name" name="name" size="20" maxlength="40" />
   </p>

   <p>
      E-mail Address:<br />
      <input type="text" id="email" name="email" size="20" maxlength="40" />
   </p>

   <input type="submit" id="submit" name = "submit" value="Go!" />
</form>

PHP:

 

function validateEmail($email)

    {
       // Create the e-mail validation regular expression
       $regexp = "~^([_a-z0-9\-]+)(\.[_a-z0-9\-]+)*@([a-z0-9\-]+)
                  (\.[a-z0-9\-]+)*(\.[a-z]{2,6})$~";

       // Validate the syntax
       if (preg_match($regexp, $email)) return true;
           else return false;
    }

PHP:

 

Still coming up as an invalid email.

 

<?php
 $email = "xx@xx.com";
 if(eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email)) {  
 echo "Valid email address."; 
} else {   
echo "Invalid email address."; 
}  
?> 

PHP:

regards...

 

preg_match('/^[^@]+@[a-zA-Z0-9._-]+\.[a-zA-Z]+$/', $email)

PHP:

preg_match pattern...

 

Yeah you can use Preg Pattern for this!

 

http://www.jooria.com/projects/view?project=940

 

preg_match is the best solution.., preg type is the good concept in php.

 

yes Preg_match is the only easy way to solve this problem

 

Just wanted to say, that the majority of email address would be in the format of if the email address your trying to validate contains any symbols or extra .dots you must allow your preg_match pattern to allow for this. So although this thread is a few days old, if you do reply, please post an example of the email address your trying to validate.