Miscellany

<input type="checkbox" id="input_id" value="100" onchange="do_ajax('my_div');" /> 

<script><!--
function do_ajax(div){
	var ajax = new Ajax();
	ajax.responseType = Ajax.FBML;
	ajax.ondone = function(data) {
			document.getElementById(div).setInnerFBML(data);
	}
	ajax.requireLogin = 1;
	var input_value = document.getElementById('input_id').getValue();
	ajax.post('http://apps.facebook.com/myapp/testajax.php?g='+input_value);
}

//--></script>


<div id="my_div">arghhhh</div>