To draw a bond/add atoms, point where you want to start a bond, hold down the (left) mouse key, drag to where you want it to end, and then release
To make a double/triple bond, draw another bond on top of the first/second
To replace an atom with the current type, click on it. Select the current atom type by clicking on "C", "O", "N", "H" buttons, selecting from the list, or typing it in the box.
To move atoms or bonds, click "Move", then grab and drag them around. To move entire drawing, click "Scroll" instead. Click "Draw" to return to drawing.
To delete atoms/bonds, click on "Del", then click on bond/atom to remove. Click "Draw" to return to drawing.
To undo the last false move(s) click "Undo", to start over fresh, click "Clear"
In such a way draw the expanded version of the following condensed structure: below: