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

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

 	
// by Nannette Thacker
// http://www.shiningstar.net
// This script checks and unchecks boxes on a form
// Checks and unchecks unlimited number in the group...
// Pass the Checkbox group name...
// call buttons as so:
// <input type=button name="CheckAll"   value="Check All"
	//onClick="checkAll(document.myform.list)">
// <input type=button name="UnCheckAll" value="Uncheck All"
	//onClick="uncheckAll(document.myform.list)">
// -->

function checkAll()
{
	//for (i = 0; i < field.length; i++)
	//field[i].checked = true ;
	//checkChange(i);



	//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') {
			inputs[i].checked = true ;
			document.getElementById('checkImage'+i).src=imgTrue;
		}
	}
	setButton();
	
}

function uncheckAll()
{
	//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') {
			inputs[i].checked = false ;
			document.getElementById('checkImage'+i).src=imgFalse;
		}
	}
	setButton();
}
function setButton()
{
	nu=0;
	but=document.getElementById('But');
	but.disabled=true;
	but.onclick=null;

	//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') {
			
				if(inputs[i].checked) {
					nu++;
				}
		
		}
	}
	if (nu>0){
		but.disabled=false;
		//but.onclick=function(){ document.myform.submit();}

	
	}


	
}


window.onload = init;