file locking over web

[puZZles]

hi, i have a bunch of xml files on a server, which can be accessed by many people. what i would like to have is that if 1 person is writing to a xml file, other users should only have read access to that file. can anyone tell me a way to implement this in c or any other way? it would be best if the xml files can be edited in notepad and then viewed in internet explorer..i am not sure how that would work with a program i write in c to take care of file locking...any ideas are appreciated.

thanks.

[iain]

i think the thing are you need is two-phase locking, the technique used on multiuser databases that stops writes when it is use. Check google - there may be some algo's already written on this.