I have a data grid that gets data dynamically from a stored proc. depending on the selection in drop down the grid should update with relevant data. the data part is working but the headers wont change when i change my selection. how can i achieve this? and also i want to hide a column on this dynamic grid.

here is the code in aspx

<asp:DropDownList ID="DropDownList1" AutoPostBack="true" runat="server" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
<asp:ListItem>Select Entity</asp:ListItem>
</asp:DropDownList>
<asp:Label runat="server" ID="EntityName"></asp:Label>
<ig:WebScriptManager ID="WebScriptManager1" runat="server"></ig:WebScriptManager>
<ig:WebDataGrid ID="EntityGrid" runat="server" Width="100%" Height="50%" StyleSetName="Claymation" >
<Columns>

</Columns>
<Behaviors>
<ig:Sorting>
</ig:Sorting>

</Behaviors>
<ClientEvents Click="NavigateOnClick" />

</ig:WebDataGrid>

and code behind

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
this.EntityGrid.DataSource = null;
this.EntityGrid.DataBind();
EntityName.Text = DropDownList1.SelectedItem.Text;
string entity = "t_" + DropDownList1.SelectedItem.Text;
String strConnString = ConfigurationManager.ConnectionStrings["LiveLeaseConnectionString"].ConnectionString;
SqlConnection con = new SqlConnection(strConnString);
SqlCommand cmd = new SqlCommand("p_DataList_ByRegardingObject", con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@RegardingObjectName", entity);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
this.EntityGrid.DataSource = ds;
this.EntityGrid.DataBind();