您好，

您可以在VS中使用"Rangevalidator"控件，该控件将允许您验证范围及其客户端验证.但是对于服务器端验证，Javascript将需要验证范围.

Hello,

You can use "Rangevalidator" control in VS which will allow you to validation range and its an client side validation .But for Server side validation Javascript will require to validate the range.

< asp:comparevalidator id ="CompareValidator1" runat ="server" xmlns:asp =#unknown">
ErrorMessage ="*您应该输入等于或大于旧值的值" ControlToValidate ="TextBox2" ControlToCompare ="TextBox1" Operator ="GreaterThanEqual" Type ="Integer">

<asp:comparevalidator id="CompareValidator1" runat="server" xmlns:asp="#unknown">
ErrorMessage="*you should input value equal to or grater then old value" ControlToValidate="TextBox2" ControlToCompare="TextBox1" Operator="GreaterThanEqual" Type="Integer">