GD-lib viser ikke valgte font!

Hej,

Når jeg vælger en font i selectboksen, hvordan får jeg den til at hente fonten i php. filen?

<table width="600" align="center" cellpadding="0" cellspacing="1">
    <tr> <td width="0" rowspan="3"></td>
    <td width="300" height="400" rowspan="2" align="center" background="image.php"><span id="me"></span></td> 
    <td><b>Skriv Tekst</b><br><input type="text" id="tekstBoks">&nbsp;

  <button onclick="setText()">OK</button>
  <br><br>

  <b>Font</b><br><form action="font.php" method="post">
            <select name="select" onchange="setFamily(this)">
              <option name="font" value="spacefr">spacefr</option>
              <option name="font" value="Zerogirl">Zerogirl
</option>
              </select></form>
    <tr>
</table>

image.php

<?php ob_start();
header("Content-type: image/jpeg");
$font = '/STORE/neovizion_dk/public_html/fonts/spacefr.ttf';
$font = '/STORE/neovizion_dk/public_html/fonts/scifixo.ttf';
$image =  '/STORE/neovizion_dk/public_html/pictures/chokobrun.jpg';             
// Create the image
$im = imagecreatefromjpeg($image);

// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);


// Add the text
imagettftext($im, 20, 0, 10, 20, $black, $font);

// Using imagepng() results in clearer text compared with imagejpeg()
imagejpeg($im);
imagedestroy($im);
?>