function doSubmit() {
    if (document.getElementById("txtName").value == "") {
        alert("请输入姓名！");
        document.getElementById("txtName").focus();
        return false;
    }
    if (document.getElementById("txtMsn").value != "") {
        if (!chkEmail(document.getElementById("txtMsn").value)) {
            alert("Msn输入错误！");
            document.getElementById("txtMsn").focus();
            return false;
        }
    }
    if (document.getElementById("txtEmail").value != "") {
        if (!chkEmail(document.getElementById("txtEmail").value)) {
            alert("电子邮件输入错误！");
            document.getElementById("txtEmail").focus();
            return false;
        }
    }
    if (document.getElementById("txtSubject").value == "") {
        alert("请输入主题！");
        document.getElementById("txtSubject").focus();
        return false;
    }
    if (document.getElementById("txtContents").value == "") {
        alert("请输入留言内容！");
        document.getElementById("txtContents").focus();
        return false;
    }
    if (document.getElementById("txtValidateCode").value == "") {
        alert("请输入验证码！");
        document.getElementById("txtValidateCode").focus();
        return false;
    }
}

function doReset() {
    this.form.reset();
    return false;
}