while accessing previous page checkbox control state . im getting object null refernce exception . due to that control is present in grid view control .
<asp:GridView ID="GridAddEmp" runat="server" AutoGenerateColumns="False" OnRowCreated="GridAddEmp_RowCreated">
<Columns>
<asp:TemplateField HeaderText="Licencing">
<ItemTemplate>
<asp:CheckBox Text="Licencing" runat="server" Width="100px" ID="chkLicencing" />
</ItemTemplate>
</asp:TemplateField>
button click event
Response.Write("<script>");
Response.Write("window.open('PurchaseOrderPrint.aspx?val=" + this.uniqueid + "','_blank')");
Response.Write("</script>");
string licencing = ((CheckBox)PreviousPage.FindControl("chkLicencing")).Checked.ToString();