Question

i have register form in asp, it has 30 input box that all of them have RequiredFieldValidator
. when user click on submit how can i found out that at least one of input is not filled and show error next to the submit button and input control?

<fieldset>
        <legend>title :</legend>
        <asp:Table ID="Table3" runat="server">
            <asp:TableRow runat="server">
                <asp:TableCell runat="server"> :</asp:TableCell>
                <asp:TableCell runat="server">
                    <asp:TextBox ID="txtMadrakTahsili" runat="server" CssClass="Width"></asp:TextBox><asp:RequiredFieldValidator ID="RequiredFieldValidator13" runat="server" 
            ErrorMessage="*" Display="Dynamic" ControlToValidate="txtMadrakTahsili"></asp:RequiredFieldValidator>
                    </asp:TableCell>
                <asp:TableCell runat="server">reshte :</asp:TableCell>
                <asp:TableCell runat="server">
                    <asp:TextBox ID="txtReshteTahsili" runat="server" CssClass="Width"></asp:TextBox><asp:RequiredFieldValidator ID="RequiredFieldValidator25" runat="server" 
            ErrorMessage="*" Display="Dynamic" ControlToValidate="txtReshteTahsili"></asp:RequiredFieldValidator></asp:TableCell>
                <asp:TableCell ID="TableCell7" runat="server">mahale akhz :</asp:TableCell>
                <asp:TableCell ID="TableCell8" runat="server">
                    <asp:TextBox ID="txtMahalAkhzMadrak" runat="server" CssClass="Width"></asp:TextBox><asp:RequiredFieldValidator ID="RequiredFieldValidator14" runat="server" 
            ErrorMessage="*" Display="Dynamic" ControlToValidate="txtMahalAkhzMadrak"></asp:RequiredFieldValidator></asp:TableCell>
            </asp:TableRow>
            <asp:TableRow runat="server">
                <asp:TableCell runat="server">avg</asp:TableCell>
                <asp:TableCell runat="server">
                    <asp:TextBox ID="txtMoadel" runat="server" CssClass="Width"></asp:TextBox><asp:RequiredFieldValidator ID="RequiredFieldValidator15" runat="server" 
            ErrorMessage="*" Display="Dynamic" ControlToValidate="txtMoadel"></asp:RequiredFieldValidator></asp:TableCell>
            </asp:TableRow>
        </asp:Table>
    </fieldset>

if one og inpuut is not filled , show error next to this button to !

<p style="float:left; clear:both;">
        <asp:Button ID="Button1" runat="server" Text="ثبت اطلاعات" Height="54px" 
            style="margin-right: 0" Width="119px" onclick="Button1_Click" /></p>

Answer 1

<asp:RequiredFieldValidator ID="RequiredFieldValidator13" runat="server" 
    ErrorMessage="The textbox is empty" Text="*" 
Display="Dynamic" ControlToValidate="txtMadrakTahsili">

When you use Text="*" it will be shown next to Textbox if you placed it near the Textbox.

The ErrorMessage property is useful when you want to show all validation errors together.

So if you want to show Error Messages associated with the Textboxes then I suggest you use ASP.NET ValidationSummary control

Validation Summary Control

EXAMPLE:

<asp:ValidationSummary ID="ValidationErrors" runat="server"
DisplayMode="BulletList" HeaderText="There are some errors on the page./>