function CheckMaillLogin() {
	var S;

	S = document.getElementById("usernameshow");
	if (S.value == "")
	{
		alert("用户名不可为空");
		S.focus();
		return(false);
	}

	S = document.getElementById("pwshow");
	if (S.value == "")
	{
		alert("密码不可为空");
		S.focus();
		return(false);
	}
	
	document.MailLogin.username.value = document.MailLogin.usernameshow.value+document.MailLogin.from.value;
	document.MailLogin.pwhidden.value = encode(document.MailLogin.pwshow.value, parseInt(document.MailLogin.picnum.value));
	//document.MailLogin.submit();
}

function encode(datastr, bassnum) {
	var tempstr;
	var tchar;
	var newdata = "";

	for (var i = 0; i < datastr.length; i++)
	{
		tchar = 65535 + bassnum - datastr.charCodeAt(i);
		tchar = tchar.toString();

		while(tchar.length < 5)
		{
			tchar = "0" + tchar;
		}

		newdata = newdata + tchar;
	}

	return newdata;
}