Zooming is very easy, it's done in 3 clicks (regular clicks, no drag&drop): First click to define the start of zoom. Second click to define the ending of zoom. Third click inside the defined zone to zoom, outside to cancel the zone.

Plugin Name (domain/hostname/plugin_name) :
Start/Stop of the graph (format:2005-08-15T15:52:01+0000) (epoch) :	/ ( / )
Limit low/high :	/
Graph size (w/o legend) (pixels):	/