function GetCookieVal(offset) 
{
        var endstr = document.cookie.indexOf (";", offset);
        if (endstr == -1)
                endstr = document.cookie.length;
        return unescape(document.cookie.substring(offset, endstr));
}
function SetCookie(name, 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] : "/";
        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 = name + "=" + escape (value) +((expires == null) ? "" : ("; expires="+ expdate.toGMTString()))
                                          +((path == null) ? "" : ("; path=" + path)) +((domain == null) ? "" : ("; domain=" + domain))
                                          +((secure == true) ? "; secure" : "");
}
function DelCookie(name)
{ 
        var exp = new Date();
        exp.setTime (exp.getTime() - 1);
        var cval = GetCookie (name);
        document.cookie = name + "=" + cval + "; expires="+ exp.toGMTString();
}
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;
                if (document.cookie.substring(i, j) == arg)
                        return GetCookieVal (j);
                i = document.cookie.indexOf(" ", i) + 1;
                if (i == 0) break;
        }
        return null;
}
function KeyDown(event)
{
    if (event.keyCode == 13)
    {
        event.returnValue=false;
        event.cancel = true;
        gook();
    }
}
function gook() {
	var U,P,save,ip;
	U = document.getElementById("usernameshow");
	if (U.value == "" || U.value == null)
	{
		alert("用户名不可为空");
		U.focus();
		return false;
	}
	P = document.getElementById("passwordshow");
	if (P.value == "" || P.value == null)
	{
		alert("密码不可为空");
		P.focus();
		return false;
	}
	save = document.getElementById("save");
	ip	 = document.getElementById("sec");
	document.login.bakecookie.value = save.checked;
	document.login.nosameip.value = ip.checked;
	document.login.username.value = U.value;
	document.login.password.value = P.value;
	if(save.checked) {
		SetCookie('extmail_username', U.value, 365 * 24 * 60 * 60);
	}else{
		DelCookie('extmail_username');
	}
	document.login.submit();
}