10. Program Control
  BASIC normally executes statements sequentially. Control
  statements let you change this sequence of execution. BASIC
  control statements can alter the sequence of program execu-
  tion at several levels:

  .
        Statement modifiers control the execution of a single
        statement.
  .
        Loops or decision blocks control the execution of a block of
        statements.
  .
        Branching statements such as GOTO and ON GOTO pass
        control to statements or local subroutines.
  .
        The EXIT and ITERATE statements explicitly control
        loops or decision blocks.
  .
        The SLEEP, WAIT, STOP and END control statements
        suspend or halt the execution of your entire program.

  This chapter describes the BASIC control statements.