How to hide asp combobox according to selected asp combobox by javascript in asp.net

I have two asp combobox one with the name of cmb_stocktype while second with the name of cmb_tagno. Now, my question is that when I select cmb_stocktype with the value of WithStock then cmb_tagno should be show else it should be hide by javascript.

Here is my following code,

<asp:DropDownList CssClass="form-control" id="cmb_stocktype" runat="server">
    <asp:ListItem Value="WithStock">WITH STOCK</asp:ListItem>
    <asp:ListItem Value="WithoutStock">WITHOUT STOCK</asp:ListItem>
</asp:DropDownList>                                    

<asp:DropDownList ID="cmb_tagno" runat="server" Style="width:90%;" CssClass="form-control" ClientIDMode="Static" ></asp:DropDownList>

$("#<%= cmb_stocktype.ClientID %>").change(function () {
    if ($("#<%= cmb_stocktype.ClientID %>").val() == "WithStock") {
        $("#<%=cmb_tagno.ClientID%>").show()
    }
    else {
        $("#<%=cmb_tagno.ClientID%>").hide()
    }
});

I used style.display and style.visibility still didn’t work.