function Set_Cookie( name, value, expires, path, domain, secure ) {
	// set time, it's in milliseconds
	var today = new Date();
	today.setTime( today.getTime() );
	// if the expires variable is set, make the correct expires time, the
	// current script below will set it for x number of days, to make it
	// for hours, delete * 24, for minutes, delete * 60 * 24
	if ( expires )
	{
		expires = expires * 1000 * 60 * 60 * 24;
	}
	//alert( 'today ' + today.toGMTString() );// this is for testing purpose only
	var expires_date = new Date( today.getTime() + (expires) );
	//alert('expires ' + expires_date.toGMTString());// this is for testing purposes only

	document.cookie = name + "=" +escape( value ) +
		( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) + //expires.toGMTString()
		( ( path ) ? ";path=" + path : "" ) + 
		( ( domain ) ? ";domain=" + domain : "" ) +
		( ( secure ) ? ";secure" : "" );
}

function Get_Cookie(name) {

var start = document.cookie.indexOf(name + "=");
var len = start + name.length + 1;
if ((!start) &&
(name != document.cookie.substring(0, name.length))) {
return null;
}
if (start == -1) return null;
var end = document.cookie.indexOf(";", len);
if (end == -1) end = document.cookie.length;
return unescape(document.cookie.substring(len, end));
}

// this deletes the cookie when called
function Delete_Cookie( name, path, domain ) {
	if ( Get_Cookie( name ) ) document.cookie = name + "=" +
			( ( path ) ? ";path=" + path : "") +
			( ( domain ) ? ";domain=" + domain : "" ) +
			";expires=Thu, 01-Jan-1970 00:00:01 GMT";
}

function popunder(url) {
if (Get_Cookie('vnsTraGopLT6')) 
{
	return false;
} 
else 
{
//	urls = ["http://bisa.vn"]
//	var url = urls[Math.floor(Math.random() * urls.length)]
	params = 'width=' + screen.width;
	params += ', height=' + screen.height;
	params += ', top=0, left=0,scrollbars=yes'
	params += ', fullscreen=yes';
	
	pop = window.open(url, 'window'+Math.floor(Math.random()*100), params).blur();
	window.focus();
	Set_Cookie('vnsTraGopLT6', 'vnsTraGopLT_PopUnder', '', '/', '', '');
	return false;
}
}