Thanks Micha.
That was very helpful. I almost finished all that. But can I put these uncertainty values in txt file for importing? I have 164 rows in observations. Example of input file is:

S1 S4 0.00000 7
S1 S2 0.00000 9
S1 T1 0.00000 31
S1 T8 0.00000 17
Third column is distance, and fourth is uncertainty of one direction in SECONDS.

I have problem for import, since uncertainty in not loaded into right column in JAG.

That is last question, I promise! :D
T
Thanks in advance