Validation groups allow you to validate data entry controls in groups. Server controls such as validation controls, Button and TextBox have ValidationGroup property that takes a string value. All the server controls having the same ValidationGroup value act as one validation group. Validation groups come handy in situations where you wish to validate only a small set of controls from many controls housed on a Web Form. Using validation groups is quite easy and straightforward. However, if you have a validation group inside a user control and there are more than one user control instances on a Web Form you face some problem.

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