;; Use this function by:
;; (setq browse-url-browser-function 'browse-url-safari)
(defun browse-url-safari (url &optional new-window)
  (interactive)
  (let ((osascript (executable-find "osascript"))
	(rc
	 (concat 
	  "tell application \"Safari\"\n"
	  "set doc to (the first document whose URL begins with \"file://%s\")\n"
	  "try\n set URL of doc to \"%s\"\n on error\n"
	  "make new document with properties {URL:\"%s\"}\n"
	  "set bounds of front window to {0, 0, 500, 600}\n"
	  "end try\nend tell")))
    (start-process 
     (concat "OS X default browser: " url)
     nil
     osascript (concat "-e " (format rc idlwave-html-help-location url url)))))