var containerDim = this.getPosition($container)
placement = placement == 'bottom' && pos.top + pos.height + actualHeight - containerDim.scroll > containerDim.height ? 'top' :
- placement == 'top' && pos.top - containerDim.scroll - actualHeight < containerDim.top ? 'bottom' :
+ placement == 'top' && pos.top - containerDim.scroll - actualHeight < containerDim.top ? 'bottom' :
placement == 'right' && pos.right + actualWidth > containerDim.width ? 'left' :
placement == 'left' && pos.left - actualWidth < containerDim.left ? 'right' :
placement