function check()
	{
		if (checkName())
			if (checkEmail())
				if (checkContent())
					document.form1.submit();
	}

	function checkName()
	{
		var name = document.form1.textfield1.value;

		if (name == "")
		{
			alert("請輸入姓名。");
			document.form1.textfield1.focus();
			document.form1.textfield1.select();
			return false;
		}
		return true;
	}

	function checkEmail()
	{
		var email = document.form1.textfield3.value;

		if (email == "")
		{
			alert("請事入電郵地址。");
			document.form1.textfield3.focus();
			document.form1.textfield3.select();
			return false;
		}
		if (email.search(/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/))
		{
			alert("電郵無效，請重申輸入。");
			document.form1.textfield3.focus();
			document.form1.textfield3.select();
			return false;
		}
		return true;
	}

	function checkContent()
	{
		var content = document.form1.textfield4.value;

		if (content == "")
		{
			alert("請輸入內容。");
			document.form1.textfield4.focus();
			document.form1.textfield4.select();
			return false;
		}
		return true;
	}