Validation controls available in ASP.NET?

How to "Upload file in a webpage" in asp.net

What is Attribute Programming? What are attributes? Where are they used?

Data Reader & Dataset

What is the difference between server side and client side code?

Why to use EnableViewState property?

• RequiredFieldValidator
• CompareValidator
• RangeValidator
• RegularExpressionValidator
• CustomValidator
• ValidationSummary

Also one can use XmlHttpRequest for validation for server side.