<%@ page language=" vb" %>
<%@ import Namespace=" System.Web.UI.WebControls" %>
<script runat=" server" >
Sub elabora( obj As Object , e As EventArgs )
If page.isValid then
lbMsg.text = " Modulo compilato correttamente"
End If
End Sub
</script>
<form runat=" server" >
Campo obbligatorio
<asp:TextBox id=" tbObb" runat=" server" />
<br>
Campo <b>NON</b> obbligatorio
<asp:TextBox id=" tbLibero" runat=" server" />
<br>
<asp:Button id=" btSubmit" runat=" server" text=" Prova" onClick=" Elabora" />
<br>
<asp:RequiredFieldValidator runat=" server" controlToValidate=" tbObb" errorMessage=" Immettere campo obbligatorio" />
<br>
<asp:Label id=" lbMsg" value=" " runat=" server" />
</form>
