jQuery Grid Plugin - jqGrid

Hi all, i've to get an xml from a php server but i've an htacces that restrict parameter that i pass to server 

ie :

http://www.balaba.com/function.....t/long/max

lat long ang max are integer

but jqgrid appen parameter after max and server reject my request.

Now ive tried a workaround i've wrote a php function that delete the extra parameters but jqgrid dont work....

I append my code here 

http://pastebin.com/ueQRng1t

and this is my jqueygrid 

http://pastebin.com/MReWmiL5

my php return xml and work good.

What's wrong? can I load my xml in a js variable by $.get call can i pass the variable to jquerygrid? How? 

Thank all and sorry for my english  

I'm (not) a Bunga-Bunga Man