ASPxValidationSummary
The ASPxValidationSummary control allows you to summarize validation errors from multiple controls and then displays them in a single block. This helps you to organize screen space more effectively if validation is required for several editors.
Main Features
Three Render Modes
You can specify the manner in which validation error texts are presented within the ASPxValidationSummary’s panel using the ASPxValidationSummary.RenderMode property. They can be displayed as the following elements:
Appearance Affected Properties 
RenderMode=Table 
RenderMode=BulletedList 
RenderMode=OrderedList Showing Error Texts as Links
Validation error texts can also serve as links, if the ASPxValidationSummary.ShowErrorAsLink property is set to true. Clicking a link in this case, moves focus to the corresponding invalid editor.
Full-Featured Client-Side API
ASPxValidationSummary provides you with a comprehensive client-side API. This API is implemented using JavaScript and is exposed via the ASPxClientValidationSummary object. The ASPxClientValidationSummary object serves as a client-side equivalent of the ASPxValidationSummary control.