dropdown box show div

[phpcodelearner]

hi every one i have searched the internet and tried many methods but i can get any of them to work
what i want to do is:
when completed is selected in a drop down box it shows a div tag
i have this currently but it is not working

<script>
function showDiv(value){
 var state = document.getElementById(email_choice).style.display;
 
 if (value == '1'){
	document.getElementById(email_choice).style.display = 'block';
 }else{
 	document.getElementById(email_choice).style.display = 'none';
 }
 
 }
</script>

<form action="<?php echo $editFormAction; ?>" method="POST" name="form3">

<select name="status" onchange="showDiv(this.value);">
      <?php
do {  
?>
      <option value="<?php echo $row_job_status['id']?>"<?php if (!(strcmp($row_job_status['id'], $row_job['status']))) {echo "selected=\"selected\"";} ?>><?php echo $row_job_status['status']?></option>
      <?php
} while ($row_job_status = mysql_fetch_assoc($job_status));
  $rows = mysql_num_rows($job_status);
  if($rows > 0) {
      mysql_data_seek($job_status, 0);
	  $row_job_status = mysql_fetch_assoc($job_status);
  }
?>
    </select>


<div id="email_choice" style="display: none">    
 {check box here}
</div>


</form>

i am sorry for the php in there! just ignore it
that is a cut down version of my page the relivent infomation is there.

summary

when completed is selected in the drop down box the div email_choice shows it content

that is it

thanks you very much for your time

[abduraooft]

document.getElementById(email_choice)

That should be

document.getElementById("email_choice")

(or within single quotes)