I am developing a web page, which will have the link to copyright protected reference materials. I will be using some web-builder tool such as front-page or dream-weaver. The problem faced is the implementation of access control over the refrence material, which is nothing but pdf files. the control should be such that when a user is aacessing, viewing or using a file no other user user should be able to view or access that file i.e. one user, one file at a time. I am in a fix, what to do? should i use the singlethreadmodel interface of servlet or jsp to develop this control, but i am afraid that i will end up in writing 300 servlet classes each crresponding to one pdf file. Any suggestions addressing this problem? Thanking you. Pushpendra Singh.