Plane increase speed

OK, I have a plane script that works just fine. I need it to slowly increase speed just like a real plane. The way it is written just shoots it off.

var moveSpeed= 60.0;



var turnSpeed = 40.0;



var Forward : KeyCode;



var Backward : KeyCode;



var Left : KeyCode;



var Right : KeyCode;



function Update () {



if(Input.GetKey(Forward))



{

       transform.eulerAngles.z += - turnSpeed * Time.deltaTime;

    }



 if(Input.GetKey(Backward))

    {



 transform.eulerAngles.z += turnSpeed * Time.deltaTime;

    }



    if(Input.GetKey(Left))

    {

       transform.eulerAngles.x +=  turnSpeed * Time.deltaTime;

    }

    if(Input.GetKey(Right))

    {

       transform.eulerAngles.x += - turnSpeed * Time.deltaTime;

    }



    if(Input.GetButton("Jump")){

       transform.position += transform.right * - moveSpeed * Time.deltaTime;

    }



}

Any help would be appreciated.

                                Thanks, Tim

Hello, did you see there is a code formatting button at the top of the post page

if ( Input.GetKey("mouse 1") )
 {constantForce.relativeForce = 15000 * Vector3.forward
;}

this simulates thrusters on a plane by adding a constant force forwards

Here is the complete code for my plane:

var speed = 15.0;
var rotspd = 10.0 ;
var bullitPrefab : Transform;


function Update ()
{ 


if ( Input.GetKey("mouse 1") )
 {constantForce.relativeForce = 15000 * Vector3.forward
;}
else 
 {constantForce.relativeForce = Vector3.zero;}
	if(Input.GetButton("forwards"))
     { 
			  transform.eulerAngles.x += rotspd * Time.deltaTime * 7;
     }			 
	 
	      if(Input.GetButton("backwards"))
     { 
			  transform.eulerAngles.x += -rotspd * Time.deltaTime * 7;
     }		
	 
	      if(Input.GetButton("left"))
	{
			  transform.eulerAngles.y += -rotspd * Time.deltaTime * 7;
     }		
	 
	      if(Input.GetButton("right"))
     { 
             transform.eulerAngles.y += rotspd * Time.deltaTime * 7;
     }		

	
	    if(Input.GetButton("Fire1")) 
      { 
	 var bullit = Instantiate(bullitPrefab, transform.Find("spawnPoint").transform.position, Quaternion.identity);
	  bullit.rigidbody.AddForce(transform.forward *8000);
	 }
	  
}	 

/*var speed = 3.0;

var rotateSpeed = 32.0;

var bullitPrefab : Transform;

function Update ()
{ 
    var controller : CharacterController=GetComponent(CharacterController);
    
	//Rot
	transform.Rotate(0, Input.GetAxis ("Horizontal") * rotateSpeed, 0);
	
	//fwd bck
    var forward = transform.TransformDirection(Vector3(0,0,1));
    var curSpeed = speed * Input.GetAxis ("Vertical");

    controller.SimpleMove(forward * curSpeed);

	
	
if(Input.GetButtonDown("Fire1")) 
      { 
	  var bullit = Instantiate(bullitPrefab, transform.Find("spawnPoint").transform.position, Quaternion.identity);
	  bullit.rigidbody.AddForce(transform.forward *2000);
	  }
} 
*/