ANYoNE WHO HAS EVER worked with a computer has had to enter data into it somehow. Anyone who has done any Windows programming (or DOS programming, if you go back far enough) has had to write data entry screens. What is data entry without some kind of validation? Then again, what is validation? Validation is the process of the receiving data (via the keyboard, the mouse, voice, serial connections, and so on) and making sure that the data meets the specifications you have laid out. For instance, if you are looking for a number but receive a character, your validation code would ignore that character. I wrote this book because it encompasses pretty much what most Windows programmers do on a day-to-day basis. As programmers, we all work with data. We collect it, massage it, store it, retrieve it, and present results back to the user. As a matter of fact, data entry and validation are likely such constant themes throughout your programming day that I bet you don't even realize you're doing them. When most new programmers think of data entry, they think "Booooring!" What often comes to mind are endless screens oftext-based data entry fields for insurance companies. Where is the fun in that? After all, there is no chance for any creativity and after a few weeks of this kind of work, life becomes dull. It seems like assembly-line programming at its worst.