popup window

[Moxy1]

i'm new to this asp.net stuff so talk slowly.

here is what i'm trying to do. page has a gridview on it. one of the fields is a dropdown list. if the user selects a specific value than i want to a popup window to open requesting additional details. The process will get to my RegisterStartupScript(cstype, "PopupScript", cstext, true), however it does not execute the script.


Column:

        <asp:TemplateField HeaderText="Action" SortExpression="action" >
            <ItemTemplate>
                <asp:DropDownList runat="server" ID="itemRes" CssClass="resBox" AutoPostBack="true"  OnSelectedIndexChanged="Index_Change"></asp:DropDownList>
            </ItemTemplate>
        </asp:TemplateField>

Code Behind:

    protected void Index_Change(Object sender, EventArgs e)
    {
        //***Session Variables******************************************************
        string conn = HttpContext.Current.Session["conn"].ToString();
        //**************************************************************************

        GridViewRow clickedRow = ((DropDownList)sender).NamingContainer as GridViewRow;
        int rowIndex = clickedRow.RowIndex;

        DropDownList tResolution = (DropDownList)(mainGrid.Rows[rowIndex].FindControl("itemRes"));

        int resolution = Convert.ToInt32(tResolution.Text);

        if (resolution != -1)
        {
            AlertRetrieve requireNote = new AlertRetrieve();
            bool isNoteNeeded = requireNote.isOtherRes(conn, resolution);

            if (isNoteNeeded == true)
            {

        //====================================================
        Type cstype = this.GetType();

        // Get a ClientScriptManager reference from the Page class.
        ClientScriptManager cs = Page.ClientScript;

        // Check to see if the startup script is already registered.
        if (!cs.IsStartupScriptRegistered(cstype, "PopupScript"))
        {
            string cstext = "openOther();";
            cs.RegisterStartupScript(cstype, "PopupScript", cstext, true);
        }
        //====================================================
    }

javascript:

function openOther() {
    var oReturnValue = showModalDialog('/WebSite1/dashboard/othRes.aspx', null, 'unadorned:yes;dialogHeight:300px;dialogWidth:500px;status:no;center:1');

    alert(oReturnValue.forname + "\n" + oReturnValue.surname);
}