DIM s$
 
 s$ = "hello"
 
 IF UCASE$(s$) = "HELLO" THEN
   ?  "it worked!"
 END IF
 
 s$ = "GOODBYE"
 
 IF LCASE$(s$) = "hello" THEN
   ?  "hello"
 ELSE
   ?  "goodbye"
 END IF

Result:

 it worked!
 goodbye