ASP.NET

<code>
public event EventHandler SelectedIndexChanged;
protected void Page_Init(Object sender, EventArgs e)
        {
            this.SelectedIndexChanged += new EventHandler(DDL_Osic);
        }

protected void DDL_Osic(Object sender, EventArgs e)
        {
            if (this.SelectedIndexChanged != null)
               this.SelectedIndexChanged(sender, e);
            
        }
</code>

<asp:DropDownList runat="server" ID="ddlTBM" CssClass="PromptValue" Width="100%"
 AutoPostBack="true" OnSelectedIndexChanged="DDL_Osic"/>

<uc1:PromptSelecteerTBM ID="PromptTBM" runat="server"
 OnSelectedIndexChanged="PromptTBM_OSIC" />

protected void PromptTBM_OSIC(Object sender, EventArgs e)
        {
                LaadTBMZones(0);
        }