Div will not send as a form element, it is not a form tag at all. You will have to use javascript to get what is inside the div tag and save it to a form element..
Code:
function getDivContent()
{
var divObj = document.getElement("a");
alert("divObj.innerHTML");
}
Then
Code:
<input type="button" value="What is in Div" onClick="getDivContent();">
Messy, but usable. I cannot guarantee the code, but it should work, maybe a few small javascript errors, but simple enough to get how to do it, and read up on using DOM in javascript.