Gridview in user control page (ascx) is null - asp.net

Question

I have a page from where a user can search for items and so on. I use a .ascx page to display the result in a grdview.
The aspx page only has a seacrh box and a button and on button click I want to pass the value from inside the textbox to the ascx page and have the gridview populate with the result. But after debugging I found that the gridview is set to null after the button click. All other values are there and the result comes back from the database.
Can some one please help. I have been looking for a solution for last few hours and have treid a few diffeerent things but still not getting anywhere.
thanks in advance
EDIT
Here is my code
This is the aspx page.
<%# Register Src="Search.ascx" TagName="Search" TagPrefix="uc1" %>
<form id="form1" runat="server">
<div class="content">
<div style="padding:5px;">
<b>Search</b>: <asp:TextBox runat="server" ID="txtSearch" />
<asp:RequiredFieldValidator ErrorMessage="*" ValidationGroup="SearchGroup" ControlToValidate="txtSearch" ID="RequiredFieldValidator1"
runat="server" />
</div>
<div style="padding:5px;">
<asp:Button Text="Search" runat="server" ValidationGroup="SearchGroup" OnClick="btnSearch_Click" ID="btnSearch" />
</div>
</div>
<asp:ScriptManager runat="server" />
<asp:UpdatePanel runat="server">
<ContentTemplate>
<div class="Results">
<uc1:Search ID="UserControl1" runat="server" />
</div>
</ContentTemplate>
</asp:UpdatePanel>
</form>
In the ASCX page I have the following
The code behind
Dim test As Object = txtSearch.Text
Dim StockList As cls_Stock_Col = MyLOTSDB.LoadStock_Col()
Try
Dim dt As DataTable = New DataTable()
Dim dcol As New DataColumn("TradeName", GetType(System.String))
dt.Columns.Add(dcol)
'Create an ID column for adding to the Datatable
dcol = New DataColumn("PackSize", GetType(System.String))
dt.Columns.Add(dcol)
dcol = New DataColumn("PLU", GetType(System.String))
dt.Columns.Add(dcol)
dcol = New DataColumn("SOH", GetType(System.String))
dt.Columns.Add(dcol)
dcol = New DataColumn("RetailAsCurrency", GetType(System.String))
dt.Columns.Add(dcol)
For Each col As DataColumn In dt.Columns
'Declare the bound field and allocate memory for the bound field.
Dim bfield As New BoundField()
'Initalize the DataField value.
bfield.DataField = col.ColumnName
'Initialize the HeaderText field value.
Dim DisplayName As String = ""
Dim DataFormat As String = ""
Dim FieldType As Type = col.GetType()
Dim StringLength As Int32
GetFieldDetails(TheType, col.ColumnName, DisplayName, DataFormat, FieldType, StringLength)
bfield.HeaderText = DisplayName
If (DataFormat = "$0.00") Then
bfield.DataFormatString = "{0:C2}"
End If
bfield.SortExpression = "col.ColumnName"
'Add the newly created bound field to the GridView.
GridView1.Columns.Add(bfield)
Next
GridView1.DataSource = StockList
GridView1.DataBind()
Catch ex As Exception
End Try
I can debug and the error is thrown when I try to add the column to the gridview,
Thanks again

Answer 1

The aspx page only has a seacrh box and a button and on
button click I want to pass the value from inside the textbox to the ascx page
You can do this by specifying a public property on your ascx control which you can access on calling page.
Inside your ascx code behind
private string searchText ;
Public string SetSearchText
{
get { return searchText; }
set { return searchText; }
}
In your calling page on button click, just set the property of the ascx control
Inside your main page on button click
YourAscxControl.SetSearchText= yourTextBox.Text.Trim();

Answer 2

User Dynamic Content Place Holder .
Refer to following links they might help:-
http://www.denisbauer.com/ASPNETControls/DynamicControlsPlaceholder.aspx
http://www.codeproject.com/Articles/18080/Solve-Dynamic-Control-Problem-With-PostBack