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 var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}
function findCookie(name) {
	var nameEQ = name + "=";
	var isAvailable = false;
	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) != -1) {
			isAvailable = true;
			break;
		}
	}
	return isAvailable;
}
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 eraseCookie(name) {
	createCookie(name,"",-1);
}
function swapImage(imgId, imgObjArray){
	var index = 0;
	var img = document.images[imgId];
	if(findCookie("imgindex") ){
		index = Number(readCookie("imgindex"));
	}else{
		createCookie("imgindex",index,7);
	}
	if(index < imgObjArray.length){
		img.src = imgObjArray[index];
		var newIndex = Number(index) + 1;
		createCookie("imgindex",newIndex,7);
	}else{
		createCookie("imgindex",0,7);
		img.src = imgObjArray[0];
	}
		
}