DRAW POLYGON LIVE
Press the link an begin to draw a polygon by left clicking on the map. If the link is not pressed or if you have finished drawing a polygon clicking on the map does nothing. You have to repress the link.
Each left click adds a point to the polygon. A right click adds a last point to the polygon and renders it on the map.
By moving the mouse the polygon with its (clicked) points and its temporarily point (mouse cursor) is prerenderd on the map.