Javascript submit and PHP?

[Anon]

I've got a form with some PHP that runs once the form has been submitted. I had a regular button that would submit the form, but I wanted to change to some text that would cause a submission.
The problem is that when I try to submit using the text, it never does submit. Here's a sample of my submit text:

<table width="79" border="0" cellspacing="0" cellpadding="0">
<tr>
<td bgcolor='#3366FF' class='overbutton' onclick=document.form1.submit() align=center onmouseover="style.backgroundColor='#9999FF'" onmouseout="style.backgroundColor='#3333FF'"><font color=white size=1>Submit</font></td>
</tr>
</table>

I get no errors but when I hit the button it doesn't submit. It refreshes the page but I'm checking the value of $HTTP_POST_VARS['Submit']and it never gets set, although it does get set when I use the button.
Is there something special I need to do to make PHP recognize a submission from Javascript or am I just missing something?

[Anon]

One thing:

Yes, my form is named 'form1'. I've also tried to pass the form as an arguement to the submit() method, but it does the same thing.