Anyone know why I am getting errors compiling my chess program with QB64?

http://www.network54.com/Forum/190883/message/1205452584/Chess+Program+for+QB64

The QB64 QB-to-C translator did not support CALL, nor did it support this version of IF/ELSE-IF/etc:

IF PIECE = 100 THEN
CALL PAWN(A, B, XX(), YY(), NDX)
ELSEIF PIECE = 270 THEN CALL KNIGHT(A, B, XX(), YY(), NDX)
ELSEIF PIECE = 300 THEN CALL BISHOP(A, B, XX(), YY(), NDX)
ELSEIF PIECE = 500 THEN CALL ROOK(A, B, XX(), YY(), NDX)
ELSEIF PIECE = 900 THEN CALL QUEEN(A, B, XX(), YY(), NDX)
ELSE CALL KING(A, B, XX(), YY(), NDX)
END IF

I had to change it to

 IF PIECE = 100 THEN
  PAWN A, B, XX(), YY(), NDX
 ELSEIF PIECE = 270 THEN
  KNIGHT A, B, XX(), YY(), NDX
 ELSEIF PIECE = 300 THEN
  BISHOP A, B, XX(), YY(), NDX
 ELSEIF PIECE = 500 THEN
  ROOK A, B, XX(), YY(), NDX
 ELSEIF PIECE = 900 THEN
  QUEEN A, B, XX(), YY(), NDX
 ELSE
  KING A, B, XX(), YY(), NDX
 END IF

After making these modifications, the program sucessfully passed through the QB-to-C translator. However, it produced errors when compiling the C code. How did these errors come about?