Help with virtual Dub

I am only new at working with virtual dub so here is the problem,I can dub the first piece that I need of the clip and then I dub the second piece of the clip but when I save it,and play it back it only saves the last part of the clip,Could someone tell me how to save and keep all that I have dubbed,Or can you tell me where I can find a tutorial on Virtual Dub,
Im really Lost
Thankyou.

 

Here is the actual how-to arcticle http://www.afterdawn.com/articles/archive/cut_avi_with_virtualdub.cfm

hope it helps

 

Thankyou Mr Hoek for your help.