function showArrow(i) {
	document.getElementById(i).src='img/arrowSubmenu.gif'
}
function hideArrow(i) {
	document.getElementById(i).src='img/spacer.gif'
}
function cOn(td, color) {
    if(document.getElementById||(document.all && !(document.getElementById))) {
	  td.style.backgroundColor= color;
	}
}
function cOut(td,color) {
    if(document.getElementById||(document.all && !(document.getElementById))) {
	  td.style.backgroundColor= color;
	}
}

function clearField(obj) {
	obj.value = '';
}

function isEmail(string) {
    if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
        return true;
    else
        return false;
}
function isReady(form) {
    if (isEmail(document.getElementById('email').value) == false) {
        alert("Het ingevoerde emailadres is geen geldig adres.");
        form.email.focus();
        return false;
    }
    return true;
}

function showHelp() {
	if(document.getElementById('helptext').style.display=='block') {
		document.getElementById('helptext').style.display='none';
	}
	else {
		document.getElementById('helptext').style.display='block';
	}
}

function showPopup(URL,w,h,resize,scr) {  
	l = (screen.availWidth-w) / 2;
	t = (screen.availHeight-h) / 2;
	window.open(URL, "Mail", "height=" + h + ",width=" + w + ",top=" + t + ",left=" + l + ",toolbar=no,status=no,resizable=" + resize + ",scrollbars=" + scr +"");
}

function selectAllCheckboxes (objSrc,obj,chkName)
{
	var objSrc = document.getElementById(objSrc.getAttribute("name"));
	var els = document.getElementsByTagName("input");
	for (var i=0; i<els.length; i++)
	{
		if (els[i].getAttribute("type").toLowerCase() == 'checkbox') {
			if (els[i].name.indexOf(chkName) > -1) {
				if (objSrc.checked) {
					els[i].checked = true;
				} else {
					els[i].checked = false;
				}
			}
		}
	}
}