this is like my last hope guys! lol
I need to generate a diagram that looks sort of like this only 4 times bigger using data from db
my db is MySql, I don't think this is possible using php, but I saw there are a lot of grapf and charts generators in JavaScript, so I'm thinking this is not that far from that, though I haven't seen something that looks like this.
I also like to add that I don't know JS nor Ajax, so I'm trying to find out if it's possible to achive this using those scripts, and if not any other suggestions would be appreciated!

Yes it is possible. You would need a mix of PHP, JavaScript, CSS and HTML. Is this easy? No, not by a long shot, so if you want to do this yourself, you will either need to spend a lot of time learning (a year or 2, maybe more) or find something that already does everything you want.

umm I don't have a year...I can give this about 2 weeks, more than that it's just not worth it..
but what is the basic concept if I might ask?
I know basic php, html and CSS

Connect to database
Pull information
Display information

That is the basic concept. Beyond that it completely depends on how dynamic you want it, what kind of diagram, what you are diagramming...

well that is obvious and I can do that easily.
the diagram is like the one I showed in the link.
I have a DB table with records that have connection to one another. sort of like object a comes before t, and object k comes after c. it's sort of like a Gantt, that shows the order of the objects.
what I want to do is to allow people with 1 click to generate the diagram according to the data that is always changing
example- table1-
Id | pre | post

I have all the connections in the DB, what I'm trying to do is to make some sort of way to show all the connections on the page, in a graphical and simple way.
the main problem is how to connect the boxes.
I can do the boxes with the object's name with divs or pictures created with GD library..but how do I connect them?