If you read the include file, it will walk you through it.

Code:
' --- IF any of these three lines cause an error ?? Simply Comment them out to fix the problem ---- 
wsave1 var byte $A0 SYSTEM ' location for W if in bank1 
wsave2 var byte $120 SYSTEM ' location for W if in bank2 
wsave3 var byte $1A0 SYSTEM ' location for W if in bank3