jQuery Grid Plugin - jqGrid

Hi everybody,

I'm new to jqgrid but willing to use it for an intranet. But I have some problem to understand how does the communication is working between the client and the server side.

I manage well to load my data into the grid when the page open, but how do I communicate with the php for after ? For example with searching data, what variables are sent and where ?

I tried $_GET['searchString'] in my php file but it doesn't exist. If it's the right way to catch the query, that means the php page is not called ...

Please give some help or an example, I'm stuck.