ASP.Net ValidationSummary Control

ValidationSummary: The ValidationSummary control does not perform any validation but shows a summary of all errors in the page. The summary displays the values of the ErrorMessage property of all validation controls that failed validation.

The error message displayed in this control is specified by the ErrorMessage property of each validation control. If the ErrorMessage property of the validation control is not set, no error message is displayed for that validation control.

ValidationSummary additional properties (Check here for other default properties and sample):

Property	Description
DisplayMode	How to display the summary. Values are: ·         BulletList ·         List ·         SingleParagraph
ShowMessageBox	A Boolean value that specifies whether the summary should be displayed in a message box or not
ShowSummary	A Boolean value that specifies whether the ValidationSummary control should be displayed or hidden
HeaderText	Used to display header text above the errors.

  
  Control usage:

<asp:ValidationSummary ID="valSummary" runat="server"     DisplayMode = "BulletList" ShowSummary = "true" />