URGENT Help Needed fast :(

Can anyone here please tell me how to make a java program on JBuilder that lets you put a number in between 1 and 20 and gives you the fibonacci number?:confused:

We are supposed to have it print out like "Fibonacci(14) is 377.

I have the input ok, and the output, but I do not know how to use a "While" loop to compute the fib number.:(

My teacher and tutor are both unable to help me, and if I want to pass this class, I only need this final assignment to be passing (we have no final :))!

Anyone who can help me with how to use a while loop to compute a fibonacci number i would appreciate it.. all they have online for source codes are fibonacci series' (i just need the one number at a time computed) and stuff, and its all too advanced for my class (Comp Sci 100) so he would know I had help and fail me.

for those who dont remember, fibonacci is...

0 1 1 2 3 5 8 13 21 etc

Thanks a Billion in advance!:(

PS: I got saddled with the worst, least helpful teacher here...!