Form for submission

FirstName:<br /> <input type="text" name="firstname"/>
    <?php  $firstname=$_POST['firstname']; if(empty($firstname))
{
die("ERROR : Enter you firstname");
}
    ?> <br/>
LastName :<br /><input type="text" name="lastname"/>
    <?php $lastname=$_POST['lastname']; if(empty($lastname))
{
die("ERROR : Enter your lastname");
}   ?> <br/