function check_btnStart() {
    var pass = true;
    $("#t_CommodityMove").find("[tag]").each(function () {
        if (this.value.trim() == '') {
            alert($(this).parent().prev().text().trim() + "<%= Resources.Resource.Remind_Required%>");
            this.focus();
            pass = false;
            return false;
        }
    });
    if (!pass)
        return false;
    if ($("#<%= gv_Office.ClientID %>").find("[tag]").length == 0) {
        alert("<%= Resources.Resource.lbl_CommodityMoveError1%>");
        return false;
    }
    var isAbroad = $("input[id*='rbl_IsAbroad']:checked").val();
    //搬出日期開始算
    var moveDate = $("#<%=tb_MoveDate.ClientID%>").val();
    var pd = moveDate.split('-');
    var mydate = new Date(pd[0], pd[1] - 1, pd[2]);
    if (isAbroad == "0") {
        mydate.setDate(mydate.getDate() + 90);
    }
    else if (isAbroad == "1") {
        mydate.setDate(mydate.getDate() + 180);
    }
    var y = mydate.getFullYear();
    var m;
    var tempM=mydate.getMonth() + 1
    if (tempM >= 10) {
        m = tempM;
    }
    else {
        m = "0" + tempM;
    }
    var d;
    var tempD=mydate.getDate();
    if (tempD >= 10) {
        d = tempD;
    }
    else {
        d = "0" + tempD;
    }
    var newDate = y + "-" + m + "-" + d;
    $("#<%= gv_Office.ClientID %>").find("[tag]").each(function () {
        if ($(this).attr('tag') == "photo") {
            var p1 = $(this).parent().find("input[id$='hdPhoto']");
            if (p1.val() == "") {
                alert(this.value + "<%= Resources.Resource.Remind_Required%>");
                this.focus();
                pass = false;
                return false;
    }
    }
    else if ($(this).attr('tag') == "ddl") {
            if (this.value.trim() == "-1") {
                alert($(this).parent().prev().text().trim() + "<%= Resources.Resource.Remind_Required%>");
                this.focus();
                pass=false;
                return false;
    }
    }
    else if (this.value.trim() == "") {
            alert($(this).parent().prev().text().trim() + "<%= Resources.Resource.Remind_Required%>");
            this.focus();
            pass=false;
            return false;
    }
    else if ($(this).attr('tag') == "number") {
            var re = /^[0-9]*[1-9][0-9]*$/;
            if (!re.test(this.value.trim())) {
                alert($(this).parent().prev().text().trim() + "<%= Resources.ResourceForm.Remind_MoreThan0%>");
                this.focus();
                pass=false;
                return false;
    }
    }
    else if ($(this).attr('tag') == "string-date") {
            if (this.value.trim() > newDate) {
                alert("<%= Resources.Resource.lbl_CommodityMoveError3%>");
                this.focus();
                pass=false;
                return false;
    }
            if (this.value.trim() < moveDate) {
                alert("<%= Resources.Resource.lbl_CommodityMoveError4%>");
                this.focus();
                pass=false;
                return false;
    }
    }
    })
        return pass;
 

}

<table class="whiteTable" id="t_CommodityMove">

<asp:TextBox ID="tb_CommodityName" runat="server" Text='<%# Eval("CommodityName") %>' tag="string"></asp:TextBox>
                </table>

、

通過查詢tag屬性來判斷裡面的元素是否為空