/* Thanks to Scott Andrew */
function addEvent(obj, evType, fn){
    if (obj.addEventListener) {
        obj.addEventListener(evType, fn, true);
        return true;
    } else if (obj.attachEvent) {
        var r = obj.attachEvent("on"+evType, fn);
        return r;
    } else {
	    return false;
    }
}

/* thanks to http://www.quirksmode.org/js/findpos.html */
function findPos(obj) {
	var curleft = curtop = 0;
	if (obj.offsetParent) {
		do {
			curleft += obj.offsetLeft;
			curtop += obj.offsetTop;
		} while (obj = obj.offsetParent);
	}
	return [curleft,curtop];
}

function createImageCheckbox(ID,imgChecked,imgUnchecked,cssClass)
{
    //get the element
    var cb = document.getElementById(ID);
    
    //create an image
    var img = document.createElement('img');
    
    //depends on the status (checked/unchecked), assigns the image
    if (cb.checked)
        img.src = imgChecked;
    else
        img.src = imgUnchecked;
    
    //set image id, css class and onclick event
    img.id = 'img_' + ID;
    img.className = cssClass;
    img.onclick = new Function('changeImageCheckboxStatus("' + ID + '","' + imgChecked + '","' + imgUnchecked + '")');
    //put the image in front of the checkbox
    cb.parentNode.insertBefore(img, cb);
    //hide the checkbox
    cb.style.display = 'none';
}

function changeImageCheckboxStatus(ID,imgChecked,imgUnchecked)
{
    //get the element
    var cb = document.getElementById(ID);
    
    if(cb.checked) 
    {
        cb.checked = '';
        document.getElementById('img_' + ID).src=imgUnchecked;
    } 
    else 
    {
        cb.checked = 'checked';
        document.getElementById('img_' + ID).src=imgChecked;
    } 
}

    function changeImage(imgIdPrefix,imageIndex)
    {
        var img, i;
        
        for(i = 0; i < 4; i++)
        {
            img = document.getElementById(imgIdPrefix+i);
            if(img)
                img.style.display='none';
        }
        img = document.getElementById(imgIdPrefix+imageIndex);
        if(img)
            img.style.display='block';
    }
    
    function hideShow(hideObj,showObj)
    {
        var obj = document.getElementById(hideObj);
        if(obj)
            obj.style.display='none';
        
        obj = document.getElementById(showObj);
        if(obj)
            obj.style.display='block';
            
        obj = document.getElementById('<%= hf.ClientID %>');
        if(obj)
            obj.value=showObj;
    }