label $w.msg -font $font -wraplength 5i -justify left -text "This canvas widget shows a mock-up of a ruler. You can create tab stops by dragging them out of the well to the right of the ruler. You can also drag existing tab stops. If you drag a tab stop far enough up or down so that it turns dim, it will be deleted when you release the mouse button."
pack $w.msg -side top
frame $w.buttons
pack $w.buttons -side bottom -expand y -fill x -pady 2m