Re: desired wage/salary on application? re: new graduates.
Keep in mind, also, that the classic rule for any financial negotiation -- salary on a new job, buying a car, buying a house,
anything -- is that
the first person to mention a specific figure "loses" (has the weaker position in the transaction). Would you voluntarily show your opponent your hand in a card game? Of course not. This is (practically) the same thing.
Let's say you are feeling very confident and assertive (or just don't know any better), and put down a figure that is significantly higher than what the hospital typically pays new grads. That by itself may get your application dropped from consideration, because the HR department will figure why should they waste time on you when the hospital has plenty of applications from new grads who are happy to take whatever the hospital offers, while you have already established you are looking for more than they want to pay.
On the other hand, let's say you happen to put down a figure that is noticeably
less than what the hospital typically pays new grads -- the HR department immediately thinks, "Hmmm, we would have willing to go as high as
X, but we won't have to in this case because s/he's willing to work for less."
The game is a lot more subtle and nuanced than that, of course, but it
is a game, and that's basically how it's played. The reason that blank is there on the application form is to
lure you into putting down a figure, but please don't do it! You have
nothing to gain by doing so. Once you name a figure, you've locked yourself into a particular position and given them the upper hand in the situation. Go through the entire interview process and make
them be the first to name a figure (and marvel at how long they'll take to do that ...

).
"Negotiable" does not at all sound like you lack confidence; it sounds like you are open to
considering whatever they may offer you. Plus, as llg noted, there are many considerations to weigh in deciding to accept a job besides how much money they're offering you, and you want to find out about and consider
all of them before you lock youself into a particular position re: money.
Nursing News