Download Counter

I'm trying to script a download counter that will display the total
number on the download page without server-side scripting.

Below is my very incomplete beginning. It returns no errors, but does
nothing:

<script language="JavaScript">
function addClicks() {
total = "form1.value";
form1.value = (eval(total.value) + (1));
}
</script>

<form name="form1" method="get">
<p><input type="text" name="total" maxlength="4" size="4"> <br>
<input type="button" name="addition" value="Download"
width="10"></p></form>