Question about user controls and DataGrids

[Jason]

I am pretty new to C# so bare with me...

The design of my website utilizes tables on every page that look almost
identical, save the data they are displaying. I have written the code
to create the body of these tables using a DataGrid, so I can
dynamically add rows to the table without modifying the HTML. Now, I
want to put this DataGrid into a user control that I can include in the
HTML code, then control the behavior of that DataGrid through functions
in the user control from the code-behind in the including page. Make
sense so far? I will try to explain a little better through an
example:

I have a page, user.aspx, that displays information about a user in
Active Directory in a table that is formatted to fit the design of the
website:

<table>
<tr>
<td>
Username
</td>
<td>
(...display username...)
</td>
</tr>
....
</table>

Now I want to pull the HTML out of the user.aspx page and put it into a
control called DefaultDisplayT able.ascx that will be included in the
HTML of the user.aspx page:

<ctrl:DefDispTb l id="tblDisplay " runat="server"> </ctrl:DefDispTbl >

In the DefaultDisplayT able.ascx, I create a DataGrid called grdUser:

<asp:datagrid id="grdUser" runat="server" datasource="<%# loTable%>"
autogeneratecol umns="False">
<columns>
<asp:boundcolum n datafield="colL abel"> </asp:boundcolumn >
<asp:boundcolum n datafield="colD ata"> </asp:boundcolumn >
</columns>
</asp:datagrid>

Then in the code-behind of this control, DefaultDisplayT able.ascx.cs, I
define a DataTable, create it's columns, etc... through a contructor
called from the code-behind of the user.aspx page, user.aspx.cs, as
well as create functions used to add rows to the table and bind the
table to the DataGrid:

public class DefaultDisplayT able : System.Web.UI.U serControl
{
protected System.Web.UI.W ebControls.Data Grid grdUser;
protected DataTable loTable;
public DefaultDisplayT able()
{
loTable = new DataTable("Data Table");

DataColumn dcLabel = new DataColumn();
dcLabel.DataTyp e = System.Type.Get Type("System.St ring");
dcLabel.ColumnN ame = "colLabel";
loTable.Columns .Add(dcLabel);

DataColumn dcData = new DataColumn();
dcData.DataType = System.Type.Get Type("System.St ring");
dcData.ColumnNa me = "colData";
loTable.Columns .Add(dcData);
}
public void Add_Table_Row(s tring lsLabelText, string lsDataText)
{
DataRow drLabel;
drLabel = loTable.NewRow( );
drLabel["colLabel"] = lsLabelText;
loTable.Rows.Ad d(drLabel);

DataRow drData;
drData = loTable.NewRow( );
drData["colData"] = lsDataText;
loTable.Rows.Ad d(drData);
}
public void Bind_DataTable( )
{
grdUser.DataBin d();
}
}

After the control is instantiated in user.aspx.cs, I would call
functions to add rows as needed:

protected rootnamespace.c ontrols.Default DisplayTable ctrlDisplay;
ctrlDisplay = new rootnamespace.c ontrols.Default DisplayTable();
ctrlDisplay.Add _Table_Row("Use rname", UsernameVariabl e);
ctrlDisplay.Bin d_DataTable();

The problem here is that when I call the Bind_DataTable( ) function, I
get the following error:

Object reference not set to an instance of an object.

Am I trying to compartmentaliz e TOO much here? Have I gone overboard?
Thanks in advance to anyone able to help!