PHP Form Results On Page

[BryanVest]

I know the php is basic and not completed yet, but I am working on that. My next step I want the result to show on index.php when a form is submitted to calculator2.php. I just cant seem to get it. Please help!

index.php

<div class="post">
        <h2 class="title">Calculator</h2>
		<hr />
         <form method="post" action="calculator2.php">
Fireplace Front Width: <input type="text" name="fw">
<br />
Fireplace Back Width: <input type="text" name="bw">
<br />
Fireplace Depth: <input type="text" name="fd">
<br />
<input type="submit" name="Submit" value="Submit">
			</form>
            Pounds Of Glass Needed: <?php echo $res1; ?>

  </div>

calculator2.php

<?php
	$frontwidth = $_POST['fw'];
	$backwidth = $_POST['bw'];
	$firedepth = $_POST['fd'];
	$x = $frontwidth + $backwidth+ $firedepth;
	$y = ($x / 3) * .6667; 
	$res1 = $y *2;
	echo $res1;
?>

[aj123cd]

TRy this

[johanafm]

Warp the code from calculator2.php in

if (isset($_POST['submit']))
{
    # original contents here
}

to the top of index.php, then change the form's action attribute to the empty string ""