- filter_has_var: documentation ( source)
- filter_input: documentation ( source)
<!DOCTYPE html>
<head><title>home</title></head>
<body>
<?php if (filter_has_var(INPUT_POST, "username")){
// the form exists, so work with it
$username=filter_input(INPUT_POST, "username");
print "<center><h1>Great going $username!<br>What type of room would you like to create?</h1></center>";
} else {
//there's no input, hence create the form
print <<<HERE
<form action="php/index.php" method="post"> <center>
<input type="text" name="fullname" placeholder="Full Name" size="25" required>
<input type="email" name="email" placeholder="Email or Mobile" size="25" required>
<input type="password" name="psw" placeholder="Password" size="25" required> </center><br>
<input type="submit" value="Here You Go!"/><br><br>
<center><h4>By clicking "Here You Go!" you agree with our terms & conditions and private policy.</h4></center> </form>
HERE;
} //end 'value exists' if ?>
</body>
</html>