FMS is free to the public
No need to buy a controller and cable from places such as Toms RC either

Go to Wahlmart or a compairable store that sells computer stuff. Find an Axis dual stick game pad. It plugs into the usb port on your PC

Down load fms at the link posted by Vic3d.
Once downloaded then go to the controls button at the top of the FMS page then click on analog control , go to mapping/calibration, set the values on the left side of the box from top to bottom as 1 3 4 2, click on calibration and follow the instructions. Now you have a dual stick controller that works like a dual stick radio transmitter, left stick operates throttle and rudder and the right stick operates ailerons and elevator. Only dif is the axis game pads sticks are spring loaded and go back to center when you let go of them.

If you still can not control the model then try pushing the button that is between the sticks on the controller.

I have been using FMS for over 6 months this way and it works great.

Do a search for a user that goes my the name ggunner. He has a par editor which allows you to adjust things on different models. Such as amount of power the model has etc.