The script looks rather good, thanks for sharing! As for your English, I thought you were English from the language you used, I had to scroll back up when I read your apology as I was confused :) !
Allow me to the comment on the usage of HTML, I don't know how fluent you are in HTML and so I don't know if this was intentional at all, but there are a lot of strict standards to stick to when sending out emails in HTML format. A lot of stand-alone email clients don't support CSS, Gmail doesn't support the <style> tag that you've used, only supports inline styles, whereas a few of the Lotus email clients barely support the floating of DIVs. This is where the use of tables is a life saver!
I've been spending a bit of time recently creating HTML formatted emails for another site of mine, Wired Flame. However, after some extensive reading, I came to the conclusion, as have many others, that creating W3C compliant XHTML emails is impractical because a lot of clients will crumble at the sight of them! You also have to be careful and ensure you avoid using rowspans and colspans as some stand-alone applications don't even support them.
It really is a nightmare. Nevertheless,
I found this website a godsend if anybody else is contemplating using HTML formatted emails!