*COMDECK  WHILE 
          TITLE  WHILE
**        WHILE  -  WHILE VERB
* 
*         EVALUATE THE EXPRESSION.  IF TRUE SIMPLY EXIT.
*         IF THE EXPRESSION IS FALSE SKIP TO AN ENDW WITH AN
*         IDENTICAL LABEL.
  
 WHILE1   BSS 
          SX6    1
          SA6    PROCESS     WHILE
          RJ     =XCCLEVX    EVALUATE EXPRESSION
  
          NZ     X5,BRWERR1  ISSUE ABORT AND EXIT 
  
          RJ     =XCCLLAB 
  
 WHILE2   BSS 
          SA4    EXPCHR 
          NZ     X4,EXIT     IF NON-NULL STRING - TRUE
          SA4    EXPVAL 
          NZ     X4,EXIT     EXIT IF EXPRESSION IS TRUE 
          NG     X4,EXIT     MINUS ZERO IS ALSO TRUE
  
          SA5    =0LENDW
          BX7    X5 
          MX6    0
          SA7    TERMT
          SA6    TERMT+1     INDICATE END OF TERMINATORS
          RJ     CSP         SKIP TO *ENDW* 
  
          JP     EXIT01      EXECUTE NEXT COMMAND 
