Performing client-side validation for Wizard steps

I have a web form that uses a Wizard with three steps. I want to perform client-side validation when the "Next" button is clicked on the first two Wizard steps and also when the "Finish" button is clicked. The first case will display errors in a Validation Summary if there are any, or go to the next step. The click on "Finish" should perform validation on the client and display any errors in the Validation Summary OR submit the form for processing. I've found a couple of posts that partially describe the solution but nothing that fully explains how to accomplish what I want. Any help would be appreciated...