Below is gridview ,i wan to set condition on absent column txtabsent value should not be empty before inserting record into database
<asp:GridView ID="gvv" runat="server" AutoGenerateColumns="False" BackColor="White" BorderColor="#CC9966" BorderStyle="None" BorderWidth="1px" CellPadding="4" >
<Columns> <asp:TemplateField HeaderText="ID">
<ItemTemplate>
<asp:Label ID="Emp_ID" runat="server" Text='<%#Bind("Emp_ID")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Name">
<ItemTemplate>
<asp:Label ID="EMp_Name" runat="server" Text='<%#Bind("EMp_Name")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="salary">
<ItemTemplate>
<asp:Label ID="EMP_Salary" runat="server" Text='<%#Bind("EMP_Salary")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<%-- <asp:TemplateField HeaderText="Allowance_Status">
<ItemTemplate>
<asp:Label ID="emp_allowance" runat="server" Text='<%#Bind("emp_allowance")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField> --%>
<asp:TemplateField HeaderText="Loan">
<ItemTemplate>
<asp:Label ID="Loan" runat="server" Text='<%#Bind("Loan")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Advance">
<ItemTemplate>
<asp:Label ID="Advance" runat="server" Text='<%#Bind("Advance")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Mobile">
<ItemTemplate>
<asp:Label ID="Mobile" runat="server" Text='<%#Bind("Mobile")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Conveyance">
<ItemTemplate>
<asp:Label ID="Conveyance" runat="server" Text='<%#Bind("Conveyance")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Medical">
<ItemTemplate>
<asp:Label ID="Medical" runat="server" Text='<%#Bind("Medical")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Food">
<ItemTemplate>
<asp:Label ID="Food" runat="server" Text='<%#Bind("Food")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Other">
<ItemTemplate>
<asp:Label ID="other" runat="server" Text='<%#Bind("other")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="OT_Hours" Visible="false">
<ItemTemplate>
<asp:Label ID="emp_OT" runat="server" Text='<%#Bind("emp_OT")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Hours" Visible="false">
<ItemTemplate>
<asp:Textbox ID="txthour" runat="server" Text='0' ></asp:Textbox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="OT_Amount" Visible="false">
<ItemTemplate>
<asp:Label ID="lbOT_Amount" runat="server" Text='<%#Bind("lbOT_Amount")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Present">
<ItemTemplate>
<asp:label ID="txtpresent" runat="server" Text='0' ></asp:label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Absent">
<ItemTemplate>
<asp:TextBox ID="txtabsent" runat="server" AutoPostBack="true" OnTextChanged="OnCalculate"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Salary">
<ItemTemplate>
<asp:label ID="txtsalary" runat="server" Text='0'></asp:label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<FooterStyle BackColor="#FFFFCC" ForeColor="#330099" />
<HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="#FFFFCC" />
<PagerStyle BackColor="#FFFFCC" ForeColor="#330099" HorizontalAlign="Center" />
<RowStyle BackColor="White" ForeColor="#330099" />
<SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="#663399" />
<SortedAscendingCellStyle BackColor="#FEFCEB" />
<SortedAscendingHeaderStyle BackColor="#AF0101" />
<SortedDescendingCellStyle BackColor="#F6F0C0" />
<SortedDescendingHeaderStyle BackColor="#7E0000" />
</asp:GridView>
