Problem with dynamic column in DatagridView

Hi, I'm having a stranger problem with datagridview and dynamic column

I'm using:

C# and Visual Studio 2005

The problem:

I created a dataset (called SellMng) inside i created a DataTable (called Products), I populate that DataTable with a procedure that executs : Select * from Product

Then in my form I bind this DataTable with a DataGridView (its work perfectly).

But I have to add (two or three columns) based on the Select, so I have something like this.

 

Name Description Complement

A         blabla        Blue  Wood New

B         ccccc        YellowWood New

C         yyyyy        Red    Maple New

 

And in the form the user can select the size of each column of the complement, so if the user select size 6:5:3 the DataGrid Should display

 

Name Description Complement            Complement1   Complement2 Complement3

A         blabla        Blue  Wood New       Blue                 Wood            New

B         ccccc        YellowWood New      Yellow              Wood            New

C         yyyyy        Red    Maple New     Red                  Maple            New

 

What I want to say is: The user can select the size of the complement and then the datagrid add columns based on the size selected by the user and the Content of the column Complement.

 

I'm alredy did that, and It is working perfectly.

I did that like this

 

dgv.Columns.Add(_columnName, _displayName);

where _columnName is columnComplement1 columnComplement2....

and  _displayName is Complement1 Complement2 Complement3....  (its inside a loop)

 

Then foreach Row in the datagridview I fill the columnComplement(x) based on the size defined by the user, something like this

foreach (DataGridRowView _row in dgv.Rows)

dgv.Rows.Current["columnComplement1"].Value = dgv.Rows.Current["columComplement"].Value.Substring(x,y);

 

Ok. everything is working perfectly

 

Now the problem: When I some column (if I click in a column Header my datagridview sort the Data base on this column) The column Complement1, Complement2, etc.... lost his value, the become blank column. Like this

 

(i Sorted by Name)

 

Name Description Complement            Complement1   Complement2 Complement3

C         yyyyy        Red    Maple New    

B         ccccc        YellowWood New     

A         blabla        Blue  Wood New      

 

The value of complement1, complment2 complement3, Just disapear.

 

What should I do ???

Thanks