error in logs

[Landy Roman]

why does it tell me running without session manager



** Message: init complete.
** Message: xfwm4: Using GTK+-2.2.0
** Message: Xinerama extension disabled
** Message: xfwm4: Running without session manager
** Message: xfce4: Running without session manager
** Message: xfce4: module mailcheck successfully loaded
** Message: xfce4: module clock successfully loaded
** Message: xfce4: module trash successfully loaded
** Message: xfdesktop: running without session manager
** Message: xfce4: module switcher successfully loaded
** Message: xfce4: module systembuttons successfully loaded
** Message: xfce4: module pager successfully loaded
** Message: xfdesktop: running without session manage