Header not getting displayed

 ID="Content2" ContentPlaceHolderID="MainContentPlaceHolder" runat="server">  class="row">  class="col-md-12">  class="form-group">  class="table-responsive">  ID="gvw" runat="server" AutoGenerateColumns="false" Font-Size="9pt" BackColor="LightGoldenrodYellow" BorderColor="Tan" BorderWidth="5px" CellPadding="3" ForeColor="Black" CssClass="table table-striped" GridLines="None" BorderStyle="None" EmptyDataText="No Records Found" EmptyDataRowStyle-ForeColor="Red">  BackColor="PaleGoldenrod" />     ID = "chkAll" runat="server" AutoPostBack="true" OnCheckedChanged="OnCheckedChanged" />    ID="CheckBox1" runat="server" AutoPostBack="true" OnCheckedChanged="OnCheckedChanged" />    HeaderText = "Sr.">                                                                                          DataField="StoreCategory" HeaderText = "Type" ReadOnly="True" SortExpression="StoreCategory"/>  DataField="Name" HeaderText = "Name" ReadOnly="True" SortExpression="Name" />  DataField="Department" HeaderText = "Department" ReadOnly="True" SortExpression="Department" />  HeaderText = "Amount">                                                                                                                                       HeaderText = "Flat %">