A little php help. Pretty please?!

Warriors,

I have a website template that I am wanting to personalize for quite a few different businesses, for demo purposes only. Once they go ahead with the website I will be coding it all properly for them.

In the meantime I don't want to sit there and spend too much time on these demo sites. What I am hoping to do is have my whole website template files as normal but also a .php file with that template. I can then open this .php file and enter things such as business name, phone number, email address, etc, etc and then all the pages from that website template will automatically pull those values from that .php file. This way I don't have to go into each website page and change the page title, contact details, copyright details, etc. As I said earlier, I will do this for their actual website but not just for the demo.

I know this can be done just looking for someone who would know the exact php I need to include on each website template page to pull the variables, and exactly how to code the .php file.

I hope someone out there can help!

If you can and you need any graphics from my signature just let me know.