function hideDiv() { 
	if (document.getElementById) {
		document.getElementById('hideshow').style.visibility = 'hidden'; 
	} 
}
 
function showDiv() { 
	if (document.getElementById) { 
		document.getElementById('hideshow').style.visibility = 'visible'; 
	}
}

function checkEmail(email) {
	var filter = /^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email)) {
		alert('Please provide a valid email address.');
		return false;
	}
	return true;
}

function validator(form) {
  var elements = form.elements;
  var err = '';
  var emailfilter = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
  for (var i = 0; i < elements.length; i++) {
    if (/(^| )checkreq( |$)/.test(elements[i].className) && elements[i].value == "") {
		target = elements[i].previousSibling;
	    addClass(target, 'error');
	    err = 'yes';
	} 
	if (/(^| )checkreq( |$)/.test(elements[i].className) && elements[i].value != "") {
  	   	target = elements[i].previousSibling;
	    removeClass(target, 'error');
	}
	if (/(^| )checkemail( |$)/.test(elements[i].className) && !emailfilter.test(elements[i].value)) {
		target = elements[i].previousSibling;		
	    addClass(target, 'error');
	    err = 'yes';
	}
	else if (/(^| )checkemail( |$)/.test(elements[i].className) && emailfilter.test(elements[i].value)) {
		target = elements[i].previousSibling;		
	    removeClass(target, 'error');
	}
  }
  if (err == 'yes') { return false; }
  else { return true; }
}
function addClass(target, classValue) {
  var pattern = new RegExp("(^| )" + classValue + "( |$)");
  if (!pattern.test(target.className)) {
    if (target.className == "") {target.className = classValue;}
	else {target.className += " " + classValue;}
  }
  return true;
}
function removeClass(target, classValue) {
  var removedClass = target.className;
  var pattern = new RegExp("(^| )" + classValue + "( |$)");
  removedClass = removedClass.replace(pattern, "$1");
  removedClass = removedClass.replace(/ $/, "");
  target.className = removedClass;
  return true;
}

function popup(url) {
	window.open(url,popup,'width=350px,height=250px');
	return false;
}
function confdelete () {
	if (confirm("Are you sure you want to delete?")){ return true; }
	else { return false; }
}