Whenever I make validation and assign the control to validation using ContorlToValidate.
But whenever the asp:label is connected to validation it still gives out this uncaught error.
“Sys.WebForms.PageRequestManagerServerErrorException: Sys.WebForms.PageRequestManagerServerErrorException: Control ‘labelID’ referenced by the ControlToValidate property of ‘validatorID’ cannot be validated.”
I have used CustomValidator, RegexValidator and requiredValidator.
the code goes like this.
`

<asp:GridView ......attributes...... 
     <Columns>
          <asp:TemplateField>
               <ItemPemplate>
                    <div>
                        <asp:Label ID="labelIDn" runat="server" Text='<%# Eval("text") %>'
                                   CssClass="txtSmall"></asp:Label>
                        <asp:CustomValidator ID="orderNumberValidator"
                                             ClientValidationFunction="labelValidator"
                                             ErrorMessage="validation failed" 
                                             ControlToValidate="grvTxtTransaction" 
                                             Display="Dynamic" runat="server" />
                   </div>
                 </ItemTemplate>
      <Columns>
<asp:GridView>

there was more content in the gridview and I wrote down where I am trying validation.
I have tried onservervalidate too

and this is the validator for ClientValidationFunction

function Validator(sender, args) {

    var val = args.value.toString();
    if (val == null) {
        args.IsValid = false;
    } else {
        var isInt = /^-?[0-9]*$/.test(args.value);
        if (isInt) {
            args.IsValid = true;
        } else {
            args.IsValid = false;
        }
    }
}

and when I try onserviervalidate, it still shares same loging but in c#

Tried different type of validation