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

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

//loginstr为登录后转向的地址，当loginstr为空时默认转向http://www.wowchina.com
function login(loginstr)
{
	var imgstr="";
	if (GetCookie('wowchina_cookie') == null)
	{
		if(loginstr==null)
		{
			addr='http://app.wowchina.com/wowchina/login.php';
		}
		else
		{
			addr='http://app.wowchina.com/wowchina/login.php?loginStr=' + loginstr;
		}
		imgstr='<img src="http://www.wowchina.com/newimgs/main_login_icon_sq_new.gif" width="5" height="6" border="0"> <a href='+addr+'  class="login-txt">登录</a>';
	}
	else
	{
		imgstr='<img src="http://www.wowchina.com/newimgs/main_login_icon_sq_new.gif" width="5" height="6" border="0"> <a href="http://app.wowchina.com/wowchina/logout.php" class="login-txt">登出</a>';
	}
	document.write(imgstr);
}