What is wrong with this assembly language code. I am trying to evaluate Rval-Xval-Yval - ( Wval - Zval) and save the result in eax acoording to these instructions: Rval BYTE 0FFh, Xval BYTE 8Fh, Yval BYTE 0C0h, Zval BYTE 0EFh, Wval BYTE 7Eh. My problem is that I get an error saying the instruction operands must be the same size. Here is my code below: (Please help, newbie here):

mov eax, Rval

mov eax, Xva

neg eax

mov eax, Yval

neg eax

mov ebx, Wval

sub ebx, Zval

sub eax,ebx

mov Rval, ebx