/**
 * Cookie operation
 * Use this carefully, cause some page have analog function
 */
function createCookie(name,value,expTime,path)
{
	//new Date("December 31, 9998");
	var exp  = new Date();
	exp.setTime(exp.getTime() + 30*24*60*60*1000);
	var newExpTime = expTime ? expTime : exp.toGMTString();
	var newPath = path ? path : "/";
	document.cookie = name + "=" + escape (value) + "; expires=" + newExpTime + "; path=" + newPath;
}

function readCookie(name)
{
	var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");
	if (arr = document.cookie.match(reg))
		return unescape(arr[2]);
	else return null;
}

function delCookie(name)
{
	createCookie(name, "", -1);
}