As discussed in the In Depth section of this chapter, validation summaries display a summary of the errors that have occurred in a Web page. This summary can be displayed as a list, as a bulleted list, or as a single paragraph, depending on the DisplayMode property. You also can specify if the summary should be displayed in the Web page and in a message box with the ShowSummary and ShowMessage Box properties, respectively.
There's a validation summary control in the ValidationControls example on the CD-ROM. When errors occur in other validation controls in the Web page, the validation summary control displays all the errors that have occurred, as you see in Figure 18.10. As you can see, a summary like this is great to bring all the errors in the page into one place.