<script  runat="server">
Sub submit(sender As Object, e As EventArgs)
   Literal1.Text="I love ASP.NET!"
End Sub
</script>


<!DOCTYPE html>
<html>
<body>

<form runat="server">
<asp:Literal id="Literal1" Text="I love ASP!" runat="server" />
<br><br>
<asp:Button Text="Change Text" OnClick="submit" runat="server" />
</form>

</body>
</html>