HTTPService not working.

I have an application where I send an HTTP request using HttpService.send.
It works fine when I run it using FlexBuilder but when I simply open the main.html file in web browser(directly) it stops working.
In this case to Http Request is sent and the application is of no use.

Can anyone tell me the reason. I tried searching but didn't get anything relevant.

Is your application build output directed to a web server like xampp?

I am building it locally and using the files which are in bin-release folder.

In my application I am loading data from cross domain and as i searched it needs an corss-domain policy file at the cross/data server.
But in this case the provider is third party and I dont have any control to their files/server.

What can be done to solve this? Can we configure at the client/flex side that which domains are OK to get data?