function getCookie(str){
        var tmp,reg=new RegExp("(^| )"+str+"=([^;]*)(;|$)","gi");
        if(tmp=reg.exec(document.cookie))return(tmp[2]);
        return null;
}
function setCookie(cookieName,cookieValue,DayValue)
{
	var expire = "";
	var day_value=1;
	if(DayValue!=null)
	{
		day_value=DayValue;
	}
    expire = new Date((new Date()).getTime() + day_value * 864000000);
    expire = "; expires=" + expire.toGMTString();
	document.cookie =  cookieName + "=" + cookieValue +";path=/"+ expire;
}

function delCookie(cookieName)
{
	var expire = "";
    expire = new Date((new Date()).getTime() - 1 );
    expire = "; expires=" + expire.toGMTString();
	document.cookie = cookieName + "=" + escape("") +";path=/"+ expire;
	//path=/
}