Ajaxifying an existing page

Hi,

I have an aspx page which just works fine basically it has a panel with all controls and there are 5 buttons(svae,submit,void etc) to perform operations.

Now i want to use Ajax to improve user experience like diaplying the progress while saving data,and showing a popup when the user saving or submitting or nay click event is completed.

Can anyone outline the steps to add ajax to the existing page.?

Thanks