extern void focusprev(Arg *arg); /* focuses previous visible client, arg is ignored */
extern void killclient(Arg *arg); /* kill c nicely */
extern void manage(Window w, XWindowAttributes *wa); /* manage new client */
-Client *nexttiled(Client *c); /* returns tiled successor of c */
+extern Client *nexttiled(Client *c); /* returns tiled successor of c */
extern void resize(Client *c, int x, int y,
int w, int h, Bool sizehints); /* resize with given coordinates c*/
extern void updatesizehints(Client *c); /* update the size hint variables of c */