gif = image/gif
jpg = image/pjpeg
png = image/x-png
swf = application/x-shockwave-flash
zip = application/x-zip-compressed
tar.gz = application/x-gzip-compressed


txt = text/plain
htm = text/html
html = text/html
mp3 = audio/mp3
mid = audio/mid
bmp = image/bmp
rm = application/vnd.rn-realmedia
avi = video/avi
asx = video/x-ms-asf.
mpg = video/mpeg
wmv = video/x-ms-wmv
wav = audio/wav
doc = application/msword
rtf = text/richtext
xls = application/vnd.ms-excel
pdf = application/pdf
ai = application/postscript
sit = application/x-stuffit