function toggle_ailment_bestsellers(reveal) {
	// show div of id $div, hide the rest of class 'information'
	if (revealdiv=document.getElementById(reveal)) {
		if (tabheader=document.getElementById(reveal+'-tab')) {
			// get the divs to hide
			var divs=new Array('ailments','bestsellers');
			for(var i=0; i<divs.length; i++){
				div=document.getElementById(divs[i]);
				if (div!=revealdiv) {
					div.style.display='none';
					}
				}
			for(var i=0; i<divs.length; i++){
				div=document.getElementById(divs[i]+'-tab');
				if (div!=tabheader) {
					div.className='';
					}
				}
			revealdiv.style.display='block';
			tabheader.className='focussed';
			createCookie('ailment_bestsellers',reveal,365)
			}
		}
	return false;
	}

function getElementsByClassName(className, tag, elm){
	// http://www.robertnyman.com/2005/11/07/the-ultimate-getelementsbyclassname/
	// "Revised version May 11th 2007" version
	var testClass = new RegExp("(^|\\\\s)" + className + "(\\\\s|$)");
	var tag = tag || "*";
	var elm = elm || document;
	var elements = (tag == "*" && elm.all)? elm.all : elm.getElementsByTagName(tag);
	var returnElements = [];
	var current;
	var length = elements.length;
	for(var i=0; i<length; i++){
		current = elements[i];
		if(testClass.test(current.className)){
			returnElements.push(current);
		}
	}
	return returnElements;
} // end function getElementsByClassName

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

function addListenerToEvent(obj,evtName,fnCall) {

 evtName=evtName.toLowerCase();
 doCapture=false;

 if (obj.addEventListener){
  //obj.addEventListener(evtName.replace('on',''),fnCall,doCapture);
  obj.addEventListener(evtName.replace('on',''),
  function(){eval(fnCall);},false);
 }
 else if(obj.attachEvent){
  obj.attachEvent(evtName,function(){eval(fnCall);});
  //also do detachEvent later
 }
 else{
  eval(obj+"."+evtName +"="+ fnCall);
 }
}

function checkQty(form) {
	var validQty = false;
	for(var x=0;x<form.elements.length;x++) {
		if(form.elements[x].type == 'text'
			&& form.elements[x].name.substr(0,3) == 'qty'
			&& parseInt(form.elements[x].value) > 0) {
			validQty = true;
		}
	}
	
	if(validQty == false) {
		alert('Please enter a quantity before adding to your cart.');
		return false;
	}
}