Uploading?

I have this upload script that I am currently modifying a little bit. I need to be able to make it so that the dumbest of the dumb can figure this thing out. The upload bar requires specific sizes and sometimes the user wont even have a logo to upload. So what I would like to do is make it so if the user clicks a certain javascript button that says. "Don't Have a Logo Click Here, Then Click Upload.?" it will prefill the box with a blank logo located on the site (so a site directory).

The code below is the upload bar(not the upload code). I am unfamiliar with javascript, so thats where I need the help.

Thanks in Advance!

<table width="500" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="">
                <tr>
<form action="upload_rename_ac.php?u=<? 
echo "$user";
?>" method="post" enctype="multipart/form-data" name="form1" id="form1">
<td>
<table width="100%" border="0" cellpadding="3" cellspacing="1" bgcolor="">
<tr>
<td><strong>Single File Upload </strong></td>
</tr>
<tr>
<td>Select file
<input name="ufile" type="file"  id="ufile" size="50" /></td>
</tr>
<tr>
<td align="center"><input type="submit" name="Submit" value="Upload" /></td>
</tr>
</table>
</td>
</form>
</tr>
</table>

Select allOpen in new window