(newbie question) Create object on the map using web ui?

[li pan]

Hi, I am new to Mapserver, so this question may sounds silly:-)
After reading some documents, I have a question. How could I add an
object(river, road, building etc) to the map through Mapserver's web gui?
It seems to me that all the datas are reading from vector or raster files,
and there is no way to modify the data on the fly? If the user are supposed
to draw their own maps, how could they do ? Do they need other GIS software?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-users/attachments/20060116/48d41f0c/attachment.html