title: Bind RadGrid `EditItemTemplate` DropDownList inside RadComboBox `SelectedIndexChanged` event, this RadComboBox is outside of RadGrid
body: <p><br/>
  <strong>HTML code:</strong> </p>
  
  <pre><code>&lt;telerik:RadComboBox ID="ddlCompany" runat="server" AutoPostBack="true"
    DataTextField="Title" DataValueField="Code"     OnSelectedIndexChanged="ddlCompany_SelectedIndexChanged"&gt;
  &lt;/telerik:RadComboBox&gt; 
  
  &lt;telerik:GridTemplateColumn UniqueName="AccountCode" HeaderText="Account Code"&gt;
     &lt;ItemTemplate&gt;
       &lt;asp:Label ID="lblAcCode" runat="server" Text='&lt;%# Eval("AccountCode")%&gt;'&gt;&lt;/asp:Label&gt;
     &lt;/ItemTemplate&gt;
     &lt;EditItemTemplate&gt;
       &lt;asp:Label ID="lblAcCode2" runat="server" Text='&lt;%# Eval("AccountCode") + " - " + Eval("AccountDescription")%&gt;' Visible="false"&gt;&lt;/asp:Label&gt;
       &lt;asp:DropDownList ID="ddlAcCode" DataTextField="AccountDescription" DataValueField="AccountCodeID" runat="server"/&gt; 
     &lt;/EditItemTemplate&gt;
  &lt;/telerik:GridTemplateColumn&gt;
  </code></pre>
  
  <p><strong>C# code:</strong></p>
  
  <pre><code>protected void RGGSTAcCode_ItemDataBound(object sender, GridItemEventArgs e)
      {
         if (e.Item is GridEditableItem &amp;&amp; e.Item.IsInEditMode)
         {
            //bind dropdwon while "Add" 
            string CompanyCode = ddlCompany.SelectedValue.ToString();
            GridEditableItem item = (GridEditableItem)e.Item;
            DropDownList ddl = (DropDownList)item.FindControl("ddlAcCode");
            ddl.DataSource = GetAccCode(CompanyCode);
            ddl.DataTextField = "AccountDescription";
            ddl.DataValueField = "AccountCodeID";
            ddl.DataBind();
            ddl.Items.Insert(0, "- Select -");
  
            //Select particular dropdown value while "Edit"
            Label lblAcCode2 = item.FindControl("lblAcCode2") as Label;
            if (lblAcCode2.Text != "- ")
            {
               ddl.SelectedItem.Text = lblAcCode2.Text;
               ddl.SelectedValue = lblAcCode2.Text;
            }
         }
  
      }
  
  protected void ddlCompany_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
  {
      //have to bind the dropdown based on RedComboBox Item
  }
  </code></pre>
  
  <p><strong>Requirement 1:</strong> I want to bind RadGrid <code>EditItemTemplate</code> DropDownList inside 
  RadComboBox <code>SelectedIndexChanged</code> event, this RadComboBox is outside of RadGrid.</p>
  
  <p><strong>Requirement 2:</strong> Want to disable "Add New" button of RadGrid with an alert msg, If RadComboBox (which is outside of RadGrid) item is not selected before clicking "Add New" button.</p>