How can I expose this control via the usercontrol to allow validation?
The error I am currently getting is as follows: ...
You will work with some controls that perform all checking automatically, requiring no code.
You will also create a custom validator with code that you write, which illustrates how you can add your own logic to the validation framework in the page.
You can test the validation state of the page and of individual controls in your own code.
NET validator controls to check user input in a Web page.
The page you create will prompt the user for an e-mail address, the number of people to reserve for, and a preferred date.
Validation controls can be organized into groups that enable you to selectively enable or disable validation for related controls on a page.
Other validation operations, such as displaying a method, can reference a specific validation group.
You enable validation of user input by adding validation controls to your page as you would add other server controls.
There are controls for different types of validation, such as range checking or pattern matching. Each validation control references an input control (a server control) elsewhere on the page.