// JavaScript Document

function decode(encodedP,decodedP) {
	var paragraphEncoded = document.getElementById(encodedP);
	var paragraphDecoded = document.getElementById(decodedP);
	var decoder = document.getElementById("decoder");
	var taglineEncoded = document.getElementById("taglineEncoded");
	var taglineDecoded = document.getElementById("taglineDecoded");
	if(paragraphEncoded.className == "hidden") {
		paragraphEncoded.className = "shown";
		paragraphDecoded.className = "hidden";
		taglineDecoded.className = "hidden";
		taglineEncoded.className = "shown";
		decoder.className = "";
	} else {
		paragraphEncoded.className = "hidden";
		paragraphDecoded.className = "shown";
		taglineDecoded.className = "shown";
		taglineEncoded.className = "hidden";
		decoder.className = "active";
	}
}

function formSubmit(formName)
{
	var form = document.getElementByName(formName);
	document.forms.form.submit();
}

function validateContact(form)
{

	var err = "";

	if (form.name.value == '') {
		alert('请输入你的名字。');
		form.name.focus();
		return false;
	}
	
	if (form.email.value == '' ) {
		alert('请输入你的电邮地址。');
		form.email.focus();
		return false;
	} else {
		if (emailAddressValid(form.email.value) == false) {
			alert ('请输入有效的电邮地址。');
			form.email.focus();
			return false;
		}
	}
	
	if (form.message.value == '' ) {
		alert('请詳细说明你的需求。');
		form.message.focus();
		return false;
	}
	
return true;
}

function validateFriend(form)
{

	var err = "";

	if (form.toName.value == '') {
		alert('请输入你朋友的名字。');
		form.toName.focus();
		return false;
	}
	
	if (form.toEmail.value == '') {
		alert('请输入你朋友的电邮。');
		form.toEmail.focus();
		return false;
	} else {
		if (emailAddressValid(form.toEmail.value) == false) {
			alert ('请输入你朋友有效的电邮地址。');
			form.toEmail.focus();
			return false;
		}
	}
	
	if (form.fromName.value == '') {
		alert('请输入你的名字。');
		form.fromName.focus();
		return false;
	}
	
	if (form.fromEmail.value == '') {
		alert('请输入你的电邮地址。');
		form.fromEmail.focus();
		return false;
	} else {
		if (emailAddressValid(form.fromEmail.value) == false) {
			alert ('请输入有效的电邮地址。');
			form.fromEmail.focus();
			return false;
		}
	}
	
	if (form.messageFriend.value == '' ) {
		alert('请詳细说明你的需求。');
		form.messageFriend.focus();
		return false;
	}
}

function emailAddressValid(s)
/*
	Assumes an email address is of the form x@y.z where:
		x is one or more of the following: a-z  A-Z  0-9  _  .  -
		y is one or more of the following: a-z  A-Z  0-9
		z is one or more of the following: a-z  A-Z  0-9  .  - 
*/
{
	var emailPattern = /^[a-zA-Z0-9_\.\-]+@[a-zA-Z0-9]+\.[a-zA-Z0-9\-\.]+$/;	// emailPattern is a RegExp object.
	
	return ( emailPattern.test(s) );	// See if s matches a standard email address pattern.
}

function changeLanguage() {
window.location=document.getElementById("languagesMenu").value
}

function submitForm() {
	document.getElementById("languageForm").submit()
}