Passing Field Value To A Php Page

I am trying to pass the value of a field to a PHP file like this:

<input type="hidden" name="field1" id="field1" value="123">
<input type="hidden" name="field2" id="field2" value="456">

<a href =
"test.php?c1=document.getElementById('field1').valu e&c2=document.getElementById('field2').value[color=blue]
><img src="add.gif" border="0"></a>[/color]

In test.php, when I do:

c1=$_GET['c1'] ;
echo c1;

I get:

c1 = document.getElementById('field1').