#1
Code:
<html> 
<center> 
<form action="" method="post">
       <input type="text" name="domain">
 <br><br> 
       <input type="submit" name="submit" value="Get IP"> 
<br> 
   </form>
</html> 

<?php
       if (isset($_POST['submit'])){ 
           $url_domain = $_POST['domain']; 
           $parsed_url = parse_url($url_domain,PHP_URL_HOST);
           $domain_ip = gethostbyname($parsed_url); 
          echo "ip: $domain_ip";  
  }  
 ?>