how to search data using start and end date from to db in as

Question

I created form where i kept 2 calender and search button .

i want to search data using these date like received date and sent date from to data base.how to do this please tell ,

and dispaly in gridview which gv code i attaeched it is on same page

<div>

<p>

<label for="<%= txtstartdate.ClientID %>">

Letter Sent Date(From):</label>

<asp:TextBox ID="txtstartdate" CssClass="text-input small-input" runat="server" MaxLength="10"></asp:TextBox>

<asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="~/Admin/images/cal.jpg"

CausesValidation="false" />

<asp:RequiredFieldValidator ID="RfvStartDate" ValidationGroup="Add" SetFocusOnError="true"

runat="server" ControlToValidate="txtstartdate" Display="Dynamic" ErrorMessage="Please enter start date.">

</asp:RequiredFieldValidator>

<asp:RegularExpressionValidator ID="RevStartDate" runat="server" ControlToValidate="txtstartdate"

Display="Dynamic" ErrorMessage="Date format should be in dd/mm/yyyy." SetFocusOnError="True"

ValidationExpression="(0[1-9]|[12][0-9]|3[01])[//.](0[1-9]|1[012])[//.](19|20)\d\d"

ValidationGroup="Add">

</asp:RegularExpressionValidator>

<br />

<em><span style="font-size: 8pt; font-weight: bold; color: #459300; font-family: Verdana">Tip:-dd/mm/yyyy</span></em>

</p>

<p>

<label for="<%= txtendate.ClientID %>">

Letter Sent Date(To):</label>

<asp:TextBox ID="txtendate" CssClass="text-input small-input" CausesValidation="true"

runat="server" MaxLength="10"></asp:TextBox>

<asp:ImageButton ID="ImageButton2" runat="server" ImageUrl="~/Admin/images/cal.jpg"

CausesValidation="false" />

<asp:RegularExpressionValidator ID="RevEndDate" runat="server" ControlToValidate="txtendate"

Display="Dynamic" ErrorMessage="Date format should be in dd/mm/yyyy." SetFocusOnError="True"

ValidationExpression="(0[1-9]|[12][0-9]|3[01])[//.](0[1-9]|1[012])[//.](19|20)\d\d"

ValidationGroup="Add">

</asp:RegularExpressionValidator>

<asp:CustomValidator ID="CustValEndDate" runat="server" ClientValidationFunction="CheckExpiryDate"

ControlToValidate="txtendate" Display="Dynamic" ErrorMessage="End date must be greater than start date."

ValidationGroup="Add"></asp:CustomValidator>

<br />

<em><span style="font-size: 8pt; color: #459300; font-weight: bold; font-family: Verdana">Tip:-dd/mm/yyyy<%--If u will not enter the end date it will enter the end date after

3 months from start date--%></span></em>

</p>

<p>

<cc1:CalendarExtender ID="CalendarExtender1" runat="server" Format="dd/MM/yyyy" TargetControlID="txtstartdate"

PopupButtonID="ImageButton1">

</cc1:CalendarExtender>

<cc1:CalendarExtender ID="CalendarExtender2" runat="server" Format="dd/MM/yyyy" TargetControlID="txtstartdate">

</cc1:CalendarExtender>

<cc1:CalendarExtender ID="CalendarExtender3" runat="server" Format="dd/MM/yyyy" TargetControlID="txtendate"

PopupButtonID="ImageButton2">

</cc1:CalendarExtender>

<cc1:CalendarExtender ID="CalendarExtender4" runat="server" Format="dd/MM/yyyy" TargetControlID="txtendate">

</cc1:CalendarExtender>

</p>

<div class="form_add_new" id="trdepartmrnt" runat="server">

<div class="row form-group">

<label class="col-md-2 col-xs-12" id="lbldepartment" for="<%=ddlDepartName.ClientID %>">

Department Name<span class="redtext">* </span>:</label>

<div class="col-md-6 col-xs-12">

<asp:DropDownList ID="ddlDepartName" CssClass="form-control" runat="server" AutoPostBack="false"

CausesValidation="false">

</asp:DropDownList>

</div>

</div>

</div>

<div>

<asp:Button ID="BtnSubmit" runat="server" CssClass="btn btn-primary pull-right" ValidationGroup="Add" ToolTip="Click To Save" Text="Search" OnClick="BtnSubmit_Click" EnableTheming="True" />

</div>

</div>

<asp:Panel ID="pnllstgrd" runat="server">

<asp:GridView ID="GrdViewSend" runat="server" AutoGenerateColumns="False"

GridLines="Vertical" Width="100%" CssClass="table-responsive" PageSize="10" AllowPaging="true">

<AlternatingRowStyle CssClass="alt" />

<Columns>

<asp:TemplateField ItemStyle-CssClass="Text-Center" HeaderText="S.No.">

<ItemTemplate>

<%#Container .DataItemIndex + 1 %>

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="NO" SortExpression="no" HeaderStyle-CssClass="Text-Center">

<ItemTemplate>

<%# DataBinder.Eval(Container.DataItem, "NO")%>

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText=" Received Date" SortExpression="receivedate" HeaderStyle-CssClass="Text-Center"

ItemStyle-CssClass="Text-Center">

<ItemTemplate>

<%# DataBinder.Eval(Container.DataItem, "ReceivedDate")%>

</ItemTemplate>

</asp:TemplateField>

</Columns>

<PagerStyle CssClass="pgr" />

<RowStyle CssClass="drow" Wrap="True" />

</asp:GridView>

</asp:Panel>