function CheckData(){
    var err = "";
    var temp = "";

    if (GetCtrlValue("ctl00_cphContentFullHeader_BannerENews1_tbxFirst") == ""){ temp += "* First.\n";}
    if (GetCtrlValue("ctl00_cphContentFullHeader_BannerENews1_tbxLast") == ""){ temp += "* Last.\n";}
    if (GetCtrlValue("ctl00_cphContentFullHeader_BannerENews1_tbxEmail") == ""){ temp += "* E-mail.\n";}
    if (temp !="" ){ err= "Please input required data for completion as follow(s);\n" + temp;}
    temp = "";
    if (GetCtrlValue("ctl00_cphContentFullHeader_BannerENews1_tbxEmail") != "") {
        if (isEmail(GetCtrlValue("ctl00_cphContentFullHeader_BannerENews1_tbxEmail")) == false) { temp += "* Invalid email address.\n"; }
    }
    if (temp !="" ){ err += "Please verify the correctness of required data as follow(s);\n" + temp ;}
    return err;
}

function DoAction(ServerAction) {
    var confirmed, isSubmitted, url, err;
    confirmed = true; isSubmitted = true; url = ""; err = "";
    
    switch (ServerAction){
        case "SAVE" : isSubmitted = true; err = CheckData(); break;
    }
    
    if (isSubmitted && confirmed){
        if (err != "") {
            alert(err);
            return false;
        } else {
            return true;
        }
    }
}