How to Generate Early & Late Curve (on time based)

hi to all experts, i prepared a schedule with 550 activates and assigned that as a baseline. Right now i m updating it & my performance percentage completion is %13.45. According to my baseline my project is finishing on 12-03-2012 but after updating that schedule it is finishing on 04-05-2012 it means some variance is coming. Keeping in mind all above thing i would like to crate Early & Late Curve (time based) as per my baseline & current status. Can somebody tell me how to generate this. Thanks....... waiting for reply,,,,