<script  runat="server">
Sub submit(sender As Object, e As EventArgs)
If Page.IsValid Then
   lbl1.Text="Page is valid."
Else
   lbl1.Text="Page is not valid!!"
End If
End Sub
</script>


<html>
<body>

<form runat="server">
Enter a number from 1 to 100:
<asp:TextBox id="tbox1" runat="server" />
<br /><br />
<asp:Button Text="Submit" OnClick="submit" runat="server" />
<br /><br />
<asp:Label id="lbl1" runat="server" />
<br />
<asp:RangeValidator
ControlToValidate="tbox1"
MinimumValue="1"
MaximumValue="100"
Type="Integer"
EnableClientScript="false"
Text="The value must be from 1 to 100!"
runat="server" />
</form>

</body>
</html>