Change Polyline Width

(defun c:lw (/ *error* acdoc width ss )
  (vl-load-com)
  (defun *error* (s)
       (if acdoc (vla-endundomark acdoc))
          (cond
        ( (not s ) )
        ( (member s '("Function cancelled" "quit / exit abort") ) )
        ( (vl-exit-with-error (strcat "\n----Error:" s) ) )
   )
    (princ))
  (setq acdoc (vla-get-activedocument
            (vlax-get-acad-object)
       )
  )
  (vla-startundomark acdoc)
  (if (setq ss (ssget "_:L" '((0 . "LWPOLYLINE"))))
      (progn
    (setq width (getreal "\nEnter New Width Value:"))
    (vlax-for each (setq ss (vla-get-activeselectionset acdoc))
      (if (vlax-property-available-p each 'ConstantWidth)
        (vlax-put each 'ConstantWidth width)
      )
 )
 (vla-delete ss)
      )
    )
    (*error* nil)
    (princ))