Open and Edit a server .doc/.odt from client

Hi,

I am developing a tool in java in which i have to do the below:

Open a .doc or .odt file from a server in a client browser
Allow user to edit the file in browser and save
Upon save the document should get stored on the server.

I have checked over net for various options but all involve changes at the client end. Can this requirement be achieved without any changes at the client end?
Please please help.

I have checked over net for various options but all involve changes at the client end. Can this requirement be achieved without any changes at the client end?

No it cannot. Does MS-Sharepoint not already do this on the IE browser ? What does this have to do with servlets ?

You can't use Word for editing, but you may be able to mimic its interface in the web application. The saving (on the server) will then trigger a save (on the server side). This won't be easy though; Office doesn't cost a lot of money for nothing. Can't you use Google Docs or a similar service that has already tackled this problem?