You could do this with about 3 pages if you needed!
I just spent the last couple of hours doing something similar with flat file databases but the idea can be done with SQL databases.
Just read the content and put it into text box/es.
Upon clicking, the text box values are method=POST through tot he processing page where the original entry is deleted and the new one saved in.
I found that I couldn't delete the contenst of a flat file db so all I did was use a attribute that told PHP where to start the 'fwrite'ing. I told it to start at the begining of the file so anything afterwards woiuld be over written.
I can go into detail if you really want me to with source code (tested). Bearing in mind I don't have enormous experience with SQL db's.
Or...PM me and maybe we can come to an arrangement where I actually do this for you 🙂