harrier controls

I don't know where you got your Harrier from, there are quite a few, both freeware and payware.

To get a grip on the whole Harrier thing you should read a bit or all of the Readme files that come with Rob Barendregts gauges such as this one http://library.avsim.net/esearch.php?DLID=&Name=&FileName=rcbvcb10.zip&Author=&CatID=root

I'm quoting just one small paragraph from the Readme file:

What the VTOL gauge essentially does: when VTOL-control is activated, it overrides
the normal FS aircraft flightdynamic calculations, so complete control of the
aircraft is done by intelligent gauge code (with input from the pilot using
the normal flightcontrols like rudder, ailerons, throttle and elevator axis).
The effects control gauge adds a lot of controlled, visible effects to the aircraft.

Even if you find that you don't want to go through with the project, I suggest you download this file, it's very small, and study at least the Readme file.

Should you have trouble finding the Readme, I'll write you the Path