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.toUTCString());
}

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);
    	}
  	}
}