/*
 对cookie的基本操作

 Atwind  2006-9-12 
*/

function getCookie(key){
	var arg = key + "=";
	var alen = arg.length;
	var clen = document.cookie.length;
	var i = 0;
	while (i < clen){
		var j = i + alen;
		if (document.cookie.substring(i,j) == arg) return getCookieVal(j); 
		i = document.cookie.indexOf(" ",i) + 1;
		if (i == 0) break;
	}
	return null;

}

function setCookie(key,value){
	var expdate = new Date();
	var argv = setCookie.arguments;
	var argc = setCookie.arguments.length;
	var expires = (argc > 2) ? argv[2] : null;
	var path = (argc > 3) ? argv[3] : null;
	var domain = (argc > 4) ? argv[4] : null;
	var secure = (argc > 5) ? argv[5] : false;
	if(expires!=null) expdate.setTime(expdate.getTime() + ( expires * 1000 ));
	document.cookie = key + "=" + escape(value) +((expires == null) ? "" : ("; expires="+ expdate.toGMTString())) +((path == null) ? "" : ("; path=" + path)) +((domain == null) ? "" : ("; domain=" + domain)) +((secure == true) ? "; secure" : ""); 
}

function getCookieVal(offset){
	var endstr = document.cookie.indexOf (";", offset);
	if (endstr == -1) endstr = document.cookie.length;
	return unescape(document.cookie.substring(offset,endstr));
}

function delCookie(name){ 
	var exp = new Date(); 
	exp.setTime (exp.getTime() - 1); 
	var cval = getCookie(name); 
	document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString(); 
}