i’m trying to send a getJson call from my app to get an external JSON from PHP file. all i’m getting is a gray empty screen ? can anyone tell me what’s the problem or at least how can i debug to get the problem

here also attached the PHP file running !!

You need to provide more Information . Try to debug using Firebug , This is available for both chrome and firefox and since your using html run it in your browser and see what you get.
Do console.log(data); and see what is being outputted in your firebugs console tab. You might be running into some cross domain issue too. Use jquery ajax jquery JOSNP to over come this. just put data: jsonp .
Hope this helps you , please provide more information.