Create read & write permissions for basic access database

We have a basic access database with a front end linked to a backend database. We need the backend database compacted as it's over 50MB in size and has little data in it. We currently have two different front ends, one that allows read access and the other write as well. We need both of these front ends merged into one. As soon as it opens it asks which access level is required and a password needs to be entered to give the permission.