<!DOCTYPE html>
<html>
<body>
   <form runat="server">
     <p>ValidationGroup 1</p>
     Name:<asp:textbox id="tbName" runat=Server />
     <asp:requiredfieldvalidator id="ReqFieldVal1"
     controltovalidate="tbName"
     validationgroup="valGroup1"
     errormessage="Required" runat=Server />
     <br>
     Age:<asp:textbox id="tbAge" runat=Server />
     <asp:requiredfieldvalidator id="ReqFieldVal2"
     controltovalidate="tbAge"
     validationgroup="valGroup1"
     errormessage="Required" runat=Server />
    
     <br><br>
      <asp:button id="Button1" text="Validate"
      causesvalidation=true
     validationgroup="valGroup1" runat=Server />
      <p>ValidationGroup 2</p>
      
      City<asp:textbox id="tbCity" runat=Server />
      <asp:requiredfieldvalidator id="ReqFieldVal3"
      controltovalidate="tbCity"
     validationgroup="valGroup2"
     errormessage="Required" runat=Server />
    
     <br><br>
     <asp:button id="Button2" text="Validate"
     causesvalidation=true
     validationgroup="valGroup2" runat=Server />
   </form>
</body>
</html>