dhtmlXCombo 在母版页中报错

Question

在无母版页正常运行，一套用母板页就报错了，哪位清楚的指教一下

Answer 1

dhtmlXCombo需要引用什么JS这些的吗？

Answer 2

能引用到，我想估计是我给绑的哥DropDownList这块错误了吧

Answer 3

<asp:Content ID="Content1" ContentPlaceHolderID="header" runat="Server">    <script type="text/javascript"> 
        window.dhx_globalImgPath= "Html/js/dhtmlxCombo/codebase/imgs/"; 
    </script>    <link rel="stylesheet" type="text/css" href="Html/js/dhtmlxCombo/codebase/dhtmlxcombo.css" />    <script type="text/javascript" src="Html/js/dhtmlxCombo/codebase/dhtmlxcommon.js"></script>    <script type="text/javascript" src="Html/js/dhtmlxCombo/codebase/dhtmlxcombo.js"></script>    <script type="text/javascript" src="Html/js/dhtmlxCombo/codebase/ext/dhtmlxcombo_whp.js"></script></asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <form runat="server" id="form1">
        <div>
        <asp:DropDownList ID="ddlProject" runat="server" Width="115"></asp:DropDownList>
        <script type="text/javascript"> 
            var combo1= new dhtmlXCombo( "ddlProject" , "ddlProject" ,115); 
            combo1.enableFilteringMode(true);
        </script>
        </div>
    </form>
</asp:Content>
没嵌在母板页时正常，报错为parent为Null