function setCookie(c_name,value,expiredays) {
	var exdate=new Date()
	exdate.setDate(exdate.getDate()+expiredays)
	document.cookie=c_name + "=" + escape(value) + ((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
};

function getCookie(c_name) {
	if (document.cookie.length>0) {
		c_start=document.cookie.indexOf(c_name + "=")
		if (c_start!=-1) {
			c_start=c_start + c_name.length+1
			c_end=document.cookie.indexOf(";",c_start)
			if (c_end==-1) c_end=document.cookie.length
				return unescape(document.cookie.substring(c_start,c_end))
		};
	};
	return ""
};

function checkCookie() {
	username=getCookie('username')
	if (username!=null && username!="") {
		alert('Welcome again '+username+'!')
	} else {
		username=prompt('Please enter your name:',"")
		if (username!=null && username!="") {
			setCookie('username',username,365)
		};
	};
}