(defun c:sbla (/ l2s);Select By Layer
(setq l2s (getstring T "\nName of layer to select? (separate by comma) <select>\n"))
(if (= l2s "") (setq l2s (cdr (assoc 8 (entget (car (entsel)))))))
(setq lss (ssget "_X" (list (cons 8 l2s) (cons 410 (getvar "ctab")))))
(sssetfirst nil lss)
)