FYI the difference in "." and "," isn't a Europe/US difference. The UK also uses the decimal point "." as do most English speaking countries along with former British colonies such as India and Pakistan. Additionally Most of East Asia also uses the decimal point, including China, Japan, the Philippines, Thailand, and Malaysia. Indonesia and Vietnam are the exceptions in that region. Most of Central America and the Caribbean does too, with Cuba and the Dominican Republic being exceptions (plus a few of the smaller islands and overseas territories of European countries).

Additionally, due largely to English's influence on their development, most major computer languages use the decimal point (and don't use thousand's separators at all). Some computers and programs CAN handle input as text that uses the decimal comma, but its not universal.

Long story short though, in English you're better off using the decimal point to avoid confusion.