Customize ValidationSummary

Question

Hi, I found this question Customize ValidationSummary in ASP.NET MVC 2.

I want to create something like this in ASP.NET. What is the right Property or Method to override in ValidationSummary class when the error summary displays?

I'm doing something like

 public class CustomValidationSummary : ValidationSummary
 {
      // What method should I override here?
 }

What I want to do is instead of

Error message 1
Error message 2
Error message 3

I want to display inline separated by comma and add some text on it.

Error message 1, Error message 2 and Error message 3 have some invalid characters.

Something like that.