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 readCookie(name, _default) {
	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);
	}
	createCookie(name,_default,365);
	return _default; 
}
	
function writeCookie(name, value, days)
{
    createCookie(name, value, days)
}

function rotateWelcomeImage()
{
    var imageNo = parseInt(readCookie('welcome_image', Math.floor(Math.random()*5) + 1))
    if(imageNo == 5)
        writeCookie('welcome_image', 1)
    else
        writeCookie('welcome_image', imageNo + 1)

    var image_Filename = 'images/welcome_' + imageNo + '.gif';

    if(document.getElementById('VLPerson') != undefined)
        document.getElementById('VLPerson').style.backgroundImage = 'url(' + image_Filename + ')';				
}