How to prolong the note?

It doesn't do anything when I try to change (prolong) the duration of the note on the Edit Multiple screen. I am obviously doin something wrong. I am not using timing correct as I strictly record in 960 ticks resolution. What are the numbers to be set in the Value field, ticks?
thanks

So that's not possible in the piano roll? I don't want to edit the note by entering the new value because I don't know the value. I'll have to calculate the value for each note and that will take ages
I just want to prolong the note and just watch the tail and then stop at appropriate position. Is it possible???

I hope I understand your question correctly... Duration = PPQ

Duration of 240 = 1/16 note
Duration of 480 = 1/8 note
Duration of 960 = 1/4 note
Duration of 1920 = 1/2 note
Duration of 3840 = 1 whole note

Yeah, you can go into seq edit page or step edit page select the note you want to edit, and hold the pad down and hear the chirps (quarter notes) or see the bar getting longer in the seq edit page... but punching in the Duration directly is usually faster. If you want to make a bunch of stuff the same note length, then on the main screen tab over to where you see "Duration 100%", hit the orange Window key and you change the duration there, and set various parameters all in one shot.

Hope this helps, take care.