Tell me how to get this flight simulator code to work?

Here's the script I found for it, but I don't know how to get it correctly attached to my game object. It just shows up as a plain script, and doesn't show the variables and such.

 /*
 This is a 3D First Person Controller script that can be used to simulate anything from 
 high speed aerial combat, to submarine warfare. I have tried to make my variable names
 as descriptive as possible so you can immediately see what they affect. The variables are
 sorted by type; speed with speed, rotation with rotation ect... I have also included generic
 ranges on variables that need them; relative upper and lower variable limits. This is because 
 some of the variables have a greater effect as they approach 1, while others have greater
 impact as they approach infinity. If for some reason the ship is not doing what it is supposed to,
 check the ranges, as some variables create problems when they are set to 0 or very large values.
 
 Also note the separate script titled Space Flight Script. This script has been
 optimized to better suit space combat. The effects of gravity, drag and lift are removed
 to better simulate flight in zero-gravity space.
 
 This script uses controls based off 4 axis. I found these parameters worked well...
     Name : (Roll, Pitch, Yaw or Throttle)
     Gravity : 20
     Dead : 0.001
     Sensitivity : 1
 
 Axis for each control (Axis based off a standard flight joystick).
     Pitch: Y- Axis
     Roll: X - Axis
     Yaw: 3'rd Axis
     Throttle: 4'th - Axis
 
 How to use this script: 
 
     Drag and Drop the Transform and its Rigidbody onto the variables Flyer and
     FlyerRigidbody in the inspector panel. Remember to change the rigidbody's Drag
     value. If you dont change this, gravity will be unrealistic... (I set drag to 500)
 
     Change the variables to simulate the flight style you desire.
 
     Create a prefab of your GameObject, and back it up to a secure location.
 
     *Note: This is important because none of the variables are stored in the 
     script. If for some reason Unity crashes during testing, the variables
     are not stored when you save the javascript, but when you save the game
     project.
 
     Save often and enjoy!
 
     ~Mirage~
 */
 import System.Net;
 
 // Componants
 var flyer : Transform;
 var flyerRigidbody : Rigidbody;
 //var tail : Transform;
 var seaLevelTransform : Transform;
 
 
 // Assorted control variables. These mostly handle realism settings, change as you see fit.
     var accelerateConst: float = 5;          // Set these close to 0 to smooth out acceleration. Don't set it TO zero or you will have a division by zero error.
     var decelerateConst: float = 0.065;    // I found this value gives semi-realistic deceleration, change as you see fit.
 
     /* The ratio of MaxSpeed to Speed Const determines your true max speed. The formula is maxSpeed/SpeedConst = True Speed. 
        This way you wont have to scale your objects to make them seem like they are going fast or slow.
        MaxSpeed is what you will want to use for a GUI though.
     */ 
     static var maxSpeed : float = 100;     
     var speedConst : float = 50;
 
     var throttleConst : int = 50;
     var raiseFlapRate : float = 1;               // Smoother when close to zero
     var lowerFlapRate : float = 1;               // Smoother when close to zero
     var maxAfterburner : float = 5;          // The maximum thrust your afterburner will produce
     var afterburnerAccelerate : float = 0.5;
     var afterburnerDecelerate : float = 1;
     var liftConst : float = 7.5;             // Another arbitrary constant, change it as you see fit.
     var angleOfAttack : float = 15;         // Effective range: 0 <= angleOfAttack <= 20
     var gravityConst = 9.8;          // An arbitrary gravity constant, there is no particular reason it has to be 9.8...
     var levelFlightPercent : int = 25;
     var maxDiveForce : float = 0.1;
     var noseDiveConst : float = 0.01;
     var minSmooth : float = 0.5;
     var maxSmooth : float = 500;
     var maxControlSpeedPercent : float = 75;     // When your speed is withen the range defined by these two variables, your ship's rotation sensitivity fluxuates.
     var minControlSpeedPercent : float = 25;     // If you reach the speed defined by either of these, your ship has reached it's max or min sensitivity.
 
 
 // Rotation Variables, change these to give the effect of flying anything from a cargo plane to a fighter jet.
     var lockRotation : boolean;       // If this is checked, it locks pitch roll and yaw constants to the var rotationConst.
     var lockedRotationValue : int = 120;
     var pitchConst = 100;
     var rollConst = 100;
     var yawConst = 100;
     var ceilingMin = 1000;
     var ceilingMax = 2000;
 
 // Airplane Aerodynamics - I strongly reccomend not touching these...
     private var nosePitch : float;
     private var trueSmooth : float;
     private var smoothRotation : float;
     private var truePitch : float;
     private var trueRoll : float;
     private var trueYaw : float;
     private var trueThrust : float;
     static var trueDrag : float;
 
 // Misc. Variables
     static var afterburnerConst : float;
     static var altitude : int;
 
 
 // HUD and Heading Variables. Use these to create your insturments.
     static var trueSpeed : int;
     static var attitude : int;
     static var incidence : int;
     static var bank : int;
     static var heading : int;
 
 var ipString =&quot;127.0.0.1&quot;;
 
 var sentPitch=0;
 var sentYaw=0;
 var sentRoll=0;
 
 
 // Let the games begin!
 function Start ()
 {
     trueDrag = 0;
     afterburnerConst = 0;
     smoothRotation = minSmooth + 0.01;
     if (lockRotation == true)
     {
        pitchConst = lockedRotationValue;
        rollConst = lockedRotationValue;
        yawConst = lockedRotationValue;
        Screen.showCursor = false;
     }
     ipString=GetIP();  
 }
 
 
 function Update () 
 {
 
     // * * This section of code handles the plane's rotation.
 
     var pitch = -Input.GetAxis ("Pitch") * pitchConst;
     var roll = Input.GetAxis ("Roll") * rollConst;
     var yaw = -Input.GetAxis ("Yaw") * yawConst;
 
     pitch *=  Time.deltaTime;
     roll *= -Time.deltaTime;
     yaw *= Time.deltaTime;
 
     // Smothing Rotations...   
     if ((smoothRotation > minSmooth)&&(smoothRotation < maxSmooth))
     {
        smoothRotation = Mathf.Lerp (smoothRotation, trueThrust, (maxSpeed-(maxSpeed/minControlSpeedPercent))* Time.deltaTime);
     }
     if (smoothRotation <= minSmooth)
     {
        smoothRotation = smoothRotation +0.01;
     }
     if ((smoothRotation >= maxSmooth) &&(trueThrust < (maxSpeed*(minControlSpeedPercent/100))))
     {
        smoothRotation = smoothRotation -0.1;
     }
     trueSmooth = Mathf.Lerp (trueSmooth, smoothRotation, 5* Time.deltaTime);
     truePitch = Mathf.Lerp (truePitch, pitch, trueSmooth * Time.deltaTime);
     trueRoll = Mathf.Lerp (trueRoll, roll, trueSmooth * Time.deltaTime);
     trueYaw = Mathf.Lerp (trueYaw, yaw, trueSmooth * Time.deltaTime);
 
 
 
 
 // * * This next block handles the thrust and drag.
     var throttle = (((-(Input.GetAxis ("Throttle")))/2)*90);
 
     if(transform.position.y>ceilingMin)
     {
        //Find the percentage of thinning atmosphere
        airThinning = ((transform.position.y - ceilingMin)/(ceilingMax - ceilingMin))/20;  
        //Apply the thin atmosphere to the throttle
         throttle = throttle*airThinning;
     }
 
     if ( throttle/speedConst >= trueThrust)
     {
        trueThrust = Mathf.SmoothStep (trueThrust, throttle/speedConst, accelerateConst * Time.deltaTime);
     }
     if (throttle/speedConst < trueThrust)
     {
        trueThrust = Mathf.Lerp (trueThrust, throttle/speedConst, decelerateConst * Time.deltaTime);
     }  
 
     rigidbody.drag = liftConst*((trueThrust)*(trueThrust));
 
     if (trueThrust <= (maxSpeed/levelFlightPercent))
     {
 
        nosePitch = Mathf.Lerp (nosePitch, maxDiveForce, noseDiveConst * Time.deltaTime);
     }
     else
     {
 
        nosePitch = Mathf.Lerp (nosePitch, 0, 2* noseDiveConst * Time.deltaTime);
     }
 
     trueSpeed = ((trueThrust/2)*maxSpeed);
 
 // ** Additional Input
 
     // Airbrake
 /*  if (Input.GetButton (&quot;Airbrake&quot;))
     {
        trueDrag = Mathf.Lerp (trueDrag, trueSpeed, raiseFlapRate * Time.deltaTime);   
 
     }
 
     if ((!Input.GetButton ("Airbrake"))&&(trueDrag !=0))
     {
        trueDrag = Mathf.Lerp (trueDrag, 0, lowerFlapRate * Time.deltaTime);
     }
 
 
     // Afterburner
     if (Input.GetButton ("Afterburner"))
     {
        afterburnerConst = Mathf.Lerp (afterburnerConst, maxAfterburner, afterburnerAccelerate * Time.deltaTime);     
     }
 
     if ((!Input.GetButton ("Afterburner"))&&(afterburnerConst !=0))
     {
        afterburnerConst = Mathf.Lerp (afterburnerConst, 0, afterburnerDecelerate * Time.deltaTime);
     }
 
 */  
     // Adding nose dive when speed gets below a percent of your max speed  
     if ( ((trueSpeed - trueDrag) + afterburnerConst) <= (maxSpeed*levelFlightPercent/100))
     {
        noseDiveConst = Mathf.Lerp (noseDiveConst,maxDiveForce, (((trueSpeed - trueDrag) + afterburnerConst) - (maxSpeed * levelFlightPercent/100)) *5 *Time.deltaTime);
        flyer.Rotate(noseDiveConst,0,0,Space.World);   
     }
 
 
     // Calculating Flight Mechanics. Used mostly for the HUD.
     attitude = parseInt(-((Vector3.Angle(Vector3.up, flyer.forward))-90));
     bank = parseInt(((Vector3.Angle(Vector3.up, flyer.up))));  
     incidence = attitude + angleOfAttack;
     heading = parseInt(flyer.eulerAngles.y);
 
     if ( seaLevelTransform != null )
     {
     altitude = (flyer.transform.position.y - seaLevelTransform.transform.position.y);
     }
     //Debug.Log ((((trueSpeed - trueDrag) + afterburnerConst) - (maxSpeed * levelFlightPercent/100)));
 
 }   // End function Update( );
 
 
 function FixedUpdate () 
 {
     if (trueThrust <= maxSpeed)
     {
        // Horizontal Force
        transform.Translate(0,0,((trueSpeed - trueDrag)/100 + afterburnerConst));
     }
 
     flyerRigidbody.AddForce (0,(rigidbody.drag - gravityConst),0);
     transform.Rotate (truePitch,-trueYaw,trueRoll);
 
     Server.airSpeed=trueSpeed;
     Server.altitude=altitude;
     sentPitch=transform.localEulerAngles.x;
     sentYaw=transform.localEulerAngles.z;
     sentRoll=transform.localEulerAngles.y;
     Server.pitch=sentPitch;
     Server.yaw=sentYaw;
     Server.roll=sentRoll;
 
 
 }// End function FixedUpdateUpdate( )
 
 
 
 function OnGUI()
 {
        GUILayout.FlexibleSpace();
        GUILayout.BeginVertical("Box");
        GUILayout.Label("IP");
        GUILayout.Label(ipString);
        GUILayout.Label("Airspeed");
        GUILayout.Label(trueSpeed.ToString());
        GUILayout.Label("Altitude");
        GUILayout.Label(altitude.ToString());
        GUILayout.Label("Pitch");
        GUILayout.Label(sentPitch.ToString());
        GUILayout.Label("Roll");
        GUILayout.Label(sentRoll.ToString());
        GUILayout.Label("Yaw");
        GUILayout.Label(sentYaw.ToString());
        GUILayout.EndVertical();
        GUILayout.FlexibleSpace();
 }
 
 function GetIP():String
 {
 var strHostName:String = &quot;&quot;;
 strHostName = System.Net.Dns.GetHostName();
 
  var ipEntry:IPHostEntry = System.Net.Dns.GetHostEntry(strHostName);
 
 var addr:IPAddress[] = ipEntry.AddressList;
 
 return addr[addr.Length-1].ToString();
 
 }