//global variables that can be used by ALL the function son this page.
var inputs;
var imgFalse = 'images/inputs/false.gif';
var imgTrue  = 'images/inputs/true.gif';

//this function runs when the page is loaded, put all your other onload stuff in here too.
//function init() {
//	replaceChecks();
//}

function replaceChecks() {
	
	//get all the input fields on the page
	inputs = document.getElementsByTagName('input');

	//cycle trough the input fields
	for(var i=0; i < inputs.length; i++) {

		//check if the input is a checkbox
		if(inputs[i].getAttribute('type') == 'checkbox') {
			
			//create a new image
			var img = document.createElement('img');
			
			//check if the checkbox is checked
			if(inputs[i].checked) {
				img.src = imgTrue;
			} else {
				img.src = imgFalse;
			}

			//set image ID and onclick action
			img.id = 'checkImage'+i;
			//set image 
			img.onclick = new Function('checkChange('+i+')');
			//place image in front of the checkbox
			inputs[i].parentNode.insertBefore(img, inputs[i]);
			
			//hide the checkbox
			inputs[i].style.display='none';
		}
	}
}

//change the checkbox status and the replacement image
function checkChange(i) {

	if(inputs[i].checked) {
		inputs[i].checked = '';
		document.getElementById('checkImage'+i).src=imgFalse;
		inputs[i].onclick();
	} else {
		inputs[i].checked = 'checked';
		document.getElementById('checkImage'+i).src=imgTrue;
		inputs[i].onclick();
	}
}

function addEvent(elm, evType, fn, useCapture)
 // addEvent and removeEvent
 // cross-browser event handling for IE5+,  NS6 and Mozilla
 // By Scott Andrew
 {
   if (elm.addEventListener){
  elm.addEventListener(evType, fn, useCapture);
  return true;
   } else if (elm.attachEvent){
  var r = elm.attachEvent("on"+evType, fn);
  return r;
   } else {
  alert("Handler could not be removed");
   }
}

addEvent(window, "load", replaceChecks);

//window.onload = init;