pass the id of textbox to dropdownliast onchange event in javascript

Question

I have a dropdownlist defined:

         <asp:DropDownList Width="300px" ID="PlaceHoldersDropDownList" runat="server"
                AppendDataBoundItems="True" TabIndex="3" onchange="PasteTextInEditor 
                                    (this.options[this.selectedIndex].value), '<%= 
                                     SubjectTextBox.ClientID %>'"   >

So, I pass the selected text and a textbox ID to a javascript function. The text box is defined as:

       <asp:TextBox Width="660px" ID="SubjectTextBox" Text='<%# Bind( "Subject") %>' 
           runat="server" TabIndex="4" MaxLength="100">
        </asp:TextBox>

So, in script function, when i put alert like this :

            alert(text);    //shows selected value
            alert(editor); // shows undefined

So editor value is turning up undefined. So, can you please let me know the mistake I've been doing. I would like to save that value selected from dropdown into textbox.Please help me fixing th eproblem. Thank You

Answer 1

It looks like your bracket is in the wrong place in your "onchange": you're only passing one parameter and not the client id.

But regardless, the ClientID is not going to be parsed here. Instead, I suggest you add your onclick in the code behind, either in your Page_Load or Page_PreRender:

PlaceHoldersDropDownList.Attributes.Add("onchange", "PasteTextInEditor(this.options[this.selectedIndex].value, '" + SubjectTextBox.ClientID + "');")