[javascript-dev] event-driven list interpolation- javascript solution?

the below is pre-posted on the big list.  the only answer came from brad garton, and while i'm grateful for his attention, i'd rather implement this in a language that i can actually understand.  

is there an elegant javascript solution for this?  i'd be grateful for a push in the right direction.  my procedural programming skills have drastically withered on the vine.

i've got a series of two-item lists that look like this:

45 67
49 67
52 68
52 72
52 74

etc.

i would like to build in interpolation for those lists. so as the new 
lists come in, interpolated versions of them are added. it's ok if 
the lists come fast and furious. the above would be changed to

45 67 this is first event
46 67
47 67
48 67
49 67 here ends second event
50 67
51 68
52 68 here ends third event
52 69
52 70
52 71
52 72 here ends fourth event
52 73
52 74 here ends fifth event

take note of the slower interpolation of the second list item during 
the third event.

anyone got a cool solution for this?

best

j