Fejl i gemme script

Hej, jeg er ved at lave dette simple og meget newbee agtige script men det virker ikke. Hvorfor ikke?


<?php
  if ($load_arc) {

$lines = file($filnavn);

$output = "";

for($i=0;$i<sizeof($lines);$i++){
    $output.= $lines[$i] . "";
}


}
?>


<FORM ACTION="" METHOD="post" NAME="form">
<select name="filnavn">
    <option value="1.txt">nummer1</option>
    <option value="2.txt">nummer2</option>
</select>
<BR>
<TEXTAREA COLS="40" ROWS="9" NAME="loadarea"><?php echo $output; ?></TEXTAREA>
<BR>
<INPUT TYPE="submit" NAME="load_arc" VALUE="Load">

</FORM>



<?
  if ($gem_arc) {
  $writefilename = $filnavn;
  $writefile = fopen($writefilename, "w");
  fwrite ($writefile, $loadarea);
  fclose ($writefile);
  print("<b>saved!</b><br>");

  }
?>

<FORM ACTION="" METHOD="post" NAME="form">
<INPUT TYPE="submit" NAME="gem_arc" VALUE="Save">
</FORM>