How to check if any fields in a form are empty in php [duplicate]

Answer 1

your form is missing the method...

<form name="registrationform" action="register.php" method="post"> //here

anywyas to check the posted data u can use isset()..

Determine if a variable is set and is not NULL

if(!isset($firstname) || trim($firstname) == '')
{
   echo "You did not fill out the required fields.";
}

Answer 2

Specify POST method in form
<form name="registrationform" action="register.php" method="post">


your form code

</form>