Problem with function

[Hamed]

function input(id,where){
div = document.getElementById(id+'_'+where);
div.innerHTML = lang_bill_number+':<form action="javascript:update('+id+', '+where+');" method="post"><input type="hidden" name="id" value="'+id+'"><input type="text" size="9px" id="number"><input type="image" src="./img/button.png"></form>';
}
function update(id, where){
div = document.getElementById(id+'_elem');
div.innerHTML = "jjs";
}
This is my code
when I use : javascript:update('+id+', '+where+'); I have problem with this function and when I use javascript:update('+id+'); function work well I do not know what should I do.

[JohnN]

javascript:update(id, where)