Javascript not seeing dropdown value

[Web Services]

I have a panel and dropdown like so

<telerik:RadAjaxPanel runat="server" ID="panel" LoadingPanelID="loadingPanel">
<asp:DropDownList ID="itemDrop" runat="server"></asp:DropDownList>
    </telerik:RadAjaxPanel>
    <telerik:RadAjaxLoadingPanel ID="loadingPanel" BackgroundPosition="Center" runat="server">
        <img id="Img1" alt="Loading..." src="~/images/loading.gif" runat="server" style="border: 0px;" />
    </telerik:RadAjaxLoadingPanel>

In the code behind I attach a JS function to the onchange event of the dropdown. Here is the JS function

function showFields(id) {
    var dd = document.getElementById(id);
    var itemArr = (dd.options[dd.selectedIndex].value).split(";;;");

    var perDiv = document.getElementById("percentDiv");
    var quantDiv = document.getElementById("quantityDiv");

    var disValue = itemArr[1];
    var item = itemArr[0];

    if (item == "-1") {
        perDiv.style.display = "none";
        quantDiv.style.display = "none";
    }
    else {

        //see if we show quantity as well
        if (disValue > 0) {
            perDiv.style.display = "block";
            quantDiv.style.display = "block";
        }
        else {
            perDiv.style.display = "none";
            quantDiv.style.display = "block";
        }//if disValue > 0


    }//if item == -1
}

Basically, I pass in the client id of the drop down. It then reads the value and decides whether or not to show some text boxes. They are set to display none by default. The problem I have is, when I do a post back with the ajax panel, the text boxes go back to being hidden. I am also calling this javascript function in the page load. When I remove the ajax panel, it sees the dd and keeps the text boxes visible. However, when I add the ajaxpanel back in, the textboxes go back to hidden on the postback. Any ideas why?

[Web Services]

Any help here, this is a little urgent.

[Eyup]

Hi,

When calling a script function from the code behind and you have AJAX enabled on your page, there are some specifics:
http://demos.telerik.com/aspnet-ajax/ajax/examples/common/recreatescripts/defaultcs.aspx

Furthermore, you should wrap your script in RadScriptBlock:
http://www.telerik.com/help/aspnet-ajax/ajax-radscriptblock-radcodeblock.html

Hope this helps.

Regards,
Eyup
Telerik