Validating web form
Shannon Horn is the co-founder and chief software architect of Web Geniuses Corporation ( Hence, many times validation was not performed in a uniform manner, complex validation was difficult to implement, and Web servers were vulnerable to validation scripts being modified by malicious users.He is a Microsoft Certified Application Developer (MCAD), Microsoft Certified Solution Developer (MCSD) and a Microsoft Certified Trainer (MCT) who has been developing Microsoft Windows and Web-based solutions as well as training for over 12 years. Shannon lives in Glendale, AZ, and is married with two daughters and a son. Validating the information entered by users is an essential part of developing a professional Web-based user interface.Before you ask, and someone always does, these examples will currently work in the following browsers: Safari 5, Chrome 6, Opera 9, Firefox 4 Beta and the i Phone/i Pad.Also each browser has a slightly different default behaviour.He has been a featured speaker at many industry events including Microsoft Dev Days and the ASP. Shannon speaks and trains for companies such as App Dev ( and Learn It ( and has been a featured speaker in training videos with Learn Key. Data validation over the Web is performed in one of two locations: on the user's computer, or on the Web server.NET and Web Services Solutions conference produced by PRO. He has also worked with large corporate clients including Microsoft, Universal Studios, MGM Studios, Monster.com/Flip Dog.com, Intel, Polygram Pictures, Prudential, Micro Accounting Systems, Sky Harbor International Airport, and Southern Automated Systems on projects using Microsoft technologies such as Visual Fox Pro, Visual Studio. Most applications perform their data validation on the user's local computer.
Form validation can be implemented in a number of different ways.
Hopefully these behaviours will converge in future releases.
For these examples we have created our own valid/invalid CSS formatting to override the browser default. That's why you may see something like the following: Before you type anything into the box a red marker is shown.
Sending data is not enough — we also need to make sure that the data users fill out in forms is in the correct format we need to process it successfully, and that it won't break our applications.
We also want to help our users to fill out our forms correctly and don't get frustrated when trying to use our apps.