onClick image to display a function with PHP

[unistake]

Hi all,

 

I am trying to find out how to create a simple piece of JS together with PHP.

 

Basically, I have an image with a value and when it is clicked I want to display a form. The form information will be gathered from the mysql database, and variables will also be included within the text fields. (this data along with other inputted values will be used later with a submit button).

 

I am hoping someone could put together a template as to how to do this, or talk me through it in fairly simple terms. I know html and php but im not sure how to use php with js.

 

Thanks