In many websites about plants & horticulture you can find other than the used in Europe
scales of temperature, length, wegth or volume - Fahrenheit's degrees, inches, pounds and gallons.
This simple script will help to convert units from one system to the other.
Just type a value in the right window below
and click anywhere in the page (out of the window).
Thanks to the authors of the site owadozerne.pl for sharing the script.