This is based on the comment above, saying that I don't use the Microsoft Validators anymore, gave up on them years ago.
I indicated that I use JQuery and Javascript to validate forms. So ...
You start here,
http://learn.jquery.com/about-jquery/how-jquery-works/[
^]
Create a blank jscript file using solution explorer, name it rangeValidator.js or something, and drag the file from the solution explorer into the head tag.
<head>
<script src="jquery.js"></script>
<script src="rangeValidator.js"></script>
</head>
Write your script
function validate_40() {
var vFlag = true;
var itxtVal6_txt, itxtVal6_int, iminVal_int, imaxVal6_int;
itxtVal6_txt = $('#TextBoxLY1').val();
iminVal6_int = parseInt(itxtVal6_txt);
imaxVal6_int = parseInt(iminVal6_int * 140 / 100);
if (!some formula) {
vFlag = false;
}
return vFlag;
}
Then on your button
<asp:textbox id="TextBoxLY1" runat="server" xmlns:asp="#unknown"></asp:textbox>
<asp:button id="submit" runat="server" onclientclick="return validate_40();" xmlns:asp="#unknown"></asp:button>
I'm not going to tackle the formula, perhaps someone can edit this and fix any errors or expand on it.