Problem: Column 'xxxxxx' does not belong to table when Adding a empty row to a datagrid.

Hello, I have form that allows me to enter multiple items and perform a batch insert into the DB. I want to add a button, Add Row_Click to add aditional rows without losing the data already in the grid, But I am running into problem using the Add Row Click and receive the error: Column 'CustomerID' does not belong to table. Please tell me what I am doing wrong?


Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim DT As New DataTable
If (Not Page.IsPostBack) OrElse (Not (TypeOf Session("DT") Is DataTable)) Then

'Create Empty Datatable
'DT = CType(gvParts.DataSource, DataTable)
DT = New DataTable("AddExtraRow")
'DT.Columns.Add("LN", Type.GetType("System.String"))
DT.Columns.Add("CustomerID", Type.GetType("System.String"))
DT.Columns.Add("BarcodeAttached", Type.GetType("System.String"))
DT.Columns.Add("Barcode", Type.GetType("System.String"))
DT.Columns.Add("RevisionPart", Type.GetType("System.String"))
DT.Columns.Add("RevisionDescription", Type.GetType("System.String"))
DT.Columns.Add("ComponentLoaction", Type.GetType("System.String"))
DT.Columns.Add("LocationID", Type.GetType("System.String"))
DT.Columns.Add("Part_SerialNumber", Type.GetType("System.String"))
DT.Columns.Add("Part_number", Type.GetType("System.String"))
DT.Columns.Add("UPC", Type.GetType("System.String"))
DT.Columns.Add("unit_price", Type.GetType("System.String"))
DT.Columns.Add("PropertyTypeID", Type.GetType("System.String"))
DT.Columns.Add("ComponentClassification", Type.GetType("System.String"))
DT.Columns.Add("RecvCondition", Type.GetType("System.String"))
DT.Columns.Add("Received_Qty", Type.GetType("System.String"))
DT.Columns.Add("UOI", Type.GetType("System.String"))
DT.Columns.Add("ConditionCodeID", Type.GetType("System.String"))
DT.Columns.Add("Time_stamp_Received", Type.GetType("System.String"))
DT.Columns.Add("Remarks", Type.GetType("System.String"))

'Store the table in the Session variable
Session("DT") = DT

' Bind the DataGrid to an empty table
'gvParts.DataSource = DT
' gvParts.DataBind()

Else
' Retrieve the table from the session variable
DT = CType(Session("DT"), DataTable)
End If

End Sub

Protected Sub AddRow_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles AddRow.Click

If (IsNumeric(RowCount.Text)) Then
Dim i As Integer
For i = 1 To CInt(RowCount.Text)
Dim DT As New DataTable
Dim DR As DataRow = DT.NewRow()
DR("CustomerID") = RowCount.Text
DT.Rows.Add(DR)

'Bind & Show New row(s) in grid
gvParts.DataSource = DT
gvParts.DataBind()
Next
End If

End Sub

************************************************** **
Reference to the form below is created
*************************

Receiving Form Example
*****************************
RecivingID______ # of Line Items______ MkGrid

LineNO | Part# | PartSerial# | PartName | Qty | Remarks
---------------------------------------------------------------------------
1.
2.
3.
4
5
Add Extra Rows Click____


Place a "Make grid" button next to the # of Line Items. When the user has filled in the number and clicked the button, put something like the following in the button click method.......

Create a new datatable and populate a column with the # of Line Items:
Protected Sub MakeGrid_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles ImageButton1.Click
Dim dt As New Data.DataTable
dt.Columns.Add(New Data.DataColumn("LineNO"))
For i As Integer = 1 To tbItems.Text
Dim dr As Data.DataRow
dr = dt.NewRow
dr("LineNO") = i
dt.Rows.Add(dr)
Next
'Bind the DataTable to the DataGrid
gvParts.DataSource = dt
gvParts.DataBind()


The gridview will need to have six columns. The first one will just be a bound column to the LineNO column of the data table. The following Five columns will be template columns with text boxes :
Note I left out the other fields Template fields to save space.

<asp:GridView ID="gvParts" runat="server" AutoGenerateColumns="False">
<Columns>
<asp:BoundField DataField="PartNo" />
<asp:TemplateField HeaderText="Part #">
<ItemTemplate>
<asp:TextBox ID="part_number" runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

Then when they submit their form, I want to iterate through the rows of the gridview, getting the textbox values and inputting into database

Note I left out the other fields Template fields to save space.

Protected Sub AddReceiving_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles AddReceiving.Click

'Add new received components to the receiving table
Dim tblReceiving As New partdb.tblReceivingDataTable()
For Each gvr As GridViewRow In gvParts.Rows
If gvr.RowType = DataControlRowType.DataRow Then

'Add a new ProductsRow to the Receiving DataTable
Dim part_number As TextBox = CType(gvr.


'Add a new receiving row to the to the ReceivingDataTable
Dim newReceiving As partdb.tblReceivingRow = tblReceiving.NewtblReceivingRow()

' Assign the values from the web page
newReceiving.Part_number = part_number.Text

' Add any "default" values
newReceiving.Archive = False
newReceiving.ProcessFlag = False
newReceiving.time_stamp_entry = Date.Now
tblReceiving.AddtblReceivingRow(newReceiving)
End If
Next

End Sub