Is there any difference??

is there executional difference between the following two statements.im going to use this in before update tirgger.

i want to preupdate employees table before update for each row..which one should i use ?? can some1 explain me in detail ..thankss

IF NVL(new.emp_updatecount, 0 ) = NVL(old.emp_updatecount, 0 ) THEN
:new.emp_updatecount := NVL(old.emp_updatecount, 0 ) + 1;


IF NVL(new.emp_updatecount, -1 ) = NVL(old.emp_updatecount, -1 ) THEN
new.emp_updatecount := NVL(old.emp_updatecount, -1 ) + 1;