<?php
if(!filter_has_var(INPUT_GET, "email"))
  {
  echo("Input type does not exist");
  }
else
  {
  if (!filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL))
    {
    echo "E-Mail is not valid";
    }
  else
    {
    echo "E-Mail is valid";
    }
  }
?> 