ughh.. back to programming.. part 2

this sucks. i hate it when it gets to this part. the part where there's an error and i have no idea how to debug it. the whole thing is more or less done. the tough part is done, only left some fine tuning here and there. but there's got to be this error that has to pop up. ughh... i've spent the past couple of hours trying to find out what's wrong, look up the internet, but all to no avail. why does parsing a String into double return a null exception error?? why null? i tried displaying the String, not null leh!? is it cos it's trying to parse the reference of the String? then how come last time can, and now cannot!?!? what is the problem!?!?

man, i'm on it for so long until i now hungry liao... arrgh... this is bad.. it's so late already.. i should go and sleep.. but hungry... how sia.. i should've stopped working on it and went to sleep earlier, before i became hungry... i hope my assignment buddy finds a way around it...