function nb_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 nb_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 nb_eraseCookie(name) {
nb_createCookie(name,"",-1);
}


function back_x(){
var no_goback_flag = nb_readCookie('back_x');

if (!no_goback_flag) 
	{
	if (!top.location.search.match(/[&\?]back_x$/)) 
		{
		nb_createCookie('back_x', top.location.href);
		top.location.search += top.location.search ? '&back_x' : '?back_x';
		}
} else if (top.location.search.match(/[&\?]back_x$/)) {
top.location.href = no_goback_flag;
}

}