Textbox controls are often used to enter dates, times, currency values or preformatted numeric data such as phone numbers. A control that allows its user to only enter a specific type of data is useful for several reasons: 1. The user may do less typing if the control automatically fills in characters such as dashes or slashes. 2. The user gets immediate feedback if he/she enters an invalid character. 3. The entered data is much more likely to be valid when the user "submits" it. The classes presented in this article provide these benefits for the most popular types of data that may be entered: dates, times, decimals, integers, ..
