I have an online flash application that acts as a front end for a server application built in delphi. The server can be installed/used on a remote computer or a personal version can be downloaded and the Flash app pointed at localhost to use it. However, Flash has issues with using the POST and GET functions on the localhost, which makes uploading data files and downloading results files difficult. To get past the difficulty with downloading results files I'm planning to just have the server app serve the results file as an attachment and have the Flash app open the address of the file up in another browser window using external interface. First off, is this likely to cause similar security issues? I.E. Flash will see "localhost" in the external interface call and stop it from working the same as when I try to use POST/GET functions with localhost?

Secondly, for upload this seems just a bit little trickier, I'm planning on doing something similar, having flash use external interface to open a php script for a file upload. Is this feasible and, again, will Flash still have security issues?

Lastly, if anyone knows how to get flash to execute POST and GET functions with localhost addresses, I'd love to have that information to avoid all this jumping through hoops.