How to perform searches in jqGrid?

How to perform searches in jqGrid?

I want to know how I do searches with this plugin, I wrote the following code:

http://jsbin.com/ajifo3/edit




As you can see I'm using JSON and PHP...
I click the search button and it opens normally, but when I type a search term and submit, does not happen any changes. I've been reading the documentation and it seems that the search is passing by parameters string, did some testing with "$_GET", but without success! Does anyone know how to do this?

Thank you and sorry for my poor English,
Rodrigo Carneiro.