Sharing problem

When I share a folder members of workgroup cannot access it. They open My network places click on view workgroup computers and when they try to access my computer (danijel) from network to see shared files and folders they got error message “Access is denied” or they are prompted to type in user name and password. Sharing and Ntfs permissions are set to full control for everyone. I tryed to switch to simple file sharing but it didn’t helped. Where’s the problem? Thanks