Set Current Layer

Autolisp Codes:

(defun c:Sl(/ old_cmh sel ent laynme )
;;Author:Ganesh Shetty, Copyright © 2013 -http://autolispgs.blogspot.in
  (setq old_cmh(getvar 'cmdecho))
  (setvar 'cmdecho 0)
  (if (setq sel (car (entsel "\nSelect an Object to set Layer Current:")))
    (progn
      (setq ent(entget sel))
      (setq laynme(cdr (assoc 8 ent)))
      (command "_Layer" "set" laynme "")
      (princ (strcat "\nLayer \""   laynme "\" is  Current Now:"))
    )
  )
  (setvar 'cmdecho oldcmh)
  (princ)
)

Visual Lisp Codes:

(defun c:Sl (/ *Activedoc* *Layers* ename Sel);(S)et (L)ayer
;;Author:Ganesh Shetty, Copyright © 2013 -http://autolispgs.blogspot.in
  (vl-load-com)    ;loading Activex Support
  (setq *Activedoc* (vlax-get-property
        (vlax-get-acad-object)
        'Activedocument
      )
 *Layers*    (vlax-get-property *Activedoc* 'Layers)
  )
  (if (setq sel (car (entsel "\nSelect an Object to Set layer Current:")))
    (progn
      (setq ename(vlax-ename->vla-object sel))
      (vla-put-activelayer *Activedoc* (vla-item *layers* (vla-get-layer ename)))
      (princ (strcat "\nLayer \""   (vla-get-layer ename) "\" is  Current Now:"))
    )
  )
  (princ)
)