How do we call a function with parameters and use output returning true/false in php?

[bakertaylor28]

How do we use something like the following? I can't seem to find anything practical on how to use the true/false return or on how to supply parameters to a function.

<?php
 
function validate_email($email){
 
   $exp = "^[a-z\'0-9]+([._-][a-z\'0-9]+)*@([a-z0-9]+([._-][a-z0-9]+))+$";
 
   if(eregi($exp,$email)){
 
      if(checkdnsrr(array_pop(explode("@",$email)),"MX")){
        return true;
      }else{
        return false;
      }
 
   }else{
 
      return false;
 
   }    
}
 
?>