能帮我解释一下吗.谢谢
Function Drawbar(drvpath)dim fso,drvpathroot,d,size,totalsize,barsize
set fso=server.createobject("scripting.filesystemobject")
drvpathroot=server.mappath("images")
drvpathroot=left(drvpathroot,(instrrev(drvpathroot,"\")-1))
set d=fso.getfolder(drvpathroot)
totalsize=d.size
drvpath=server.mappath(drvpath)
set d=fso.getfolder(drvpath)
size=d.size
barsize=cint((size/totalsize)*150)
Drawbar=barsize
End Function