slow a lerp ? array/static problem

basically im using this to snap between 4 different zoom levels of a camera, that works fine, now i can't get my lerp to work gradually or be "smooth" any insight would be awesome,

i know im kinda of asking people to do it for me, but i just cannot figure out as this is new territory for me, thanks in advance :)

 #pragma strict
 var target : Transform ;
 var distance:float = 20.0;
 var switchDistance : int;
 var height : float = 10.0;
 var rotationDamping : float = 1.0;
 var rotateSpeed : float = 20.0;
 var speed : float = 0.001;
 private var heightArray : float[];
 private var lengthArray : float[];
 private var distanceArray : float[];
  var i :int;//indexes our array values by assigning them a number in our switch case
  
 function Start () {
 heightArray = [10.0, 20.0 ,30.0,40.0];
 lengthArray = [10.0, 20.0 ,30.0,40.0];
 distanceArray = [10.0, 100.0 ,150.0,400.0];
 switchDistance = 2.0;
  
 }
  
 function Update () {
     distance = distanceArray[i];  //here we actually set i as part of our array  
     if(Input.GetButton("rightMouse")){
         var h : float = rotateSpeed * Input.GetAxis ("Mouse X");
             transform.Rotate (0, h, 0);
     }
     switchDistance= Mathf.Clamp(switchDistance,0.0,4.0);
     distance = distanceArray[i];
     height = heightArray[i];
 }
  
 function LateUpdate() {
     var wantedRotationAngle = target.eulerAngles.y;
     var wantedHeight = target.transform.position.y + height;
     var currentRotationAngle = transform.eulerAngles.y;
     var currentHeight = transform.position.y;
    
        if (Input.GetAxis("mouseZoom")>0 && switchDistance <=4 ){
            Debug.Log("+");
            switchDistance -= 1 ;
        
        }  
        if (Input.GetAxis("mouseZoom")<0 && switchDistance >=0){
            switchDistance += 1 ;
        }
    
         switch (switchDistance){
        
         case 3:
             //distance = 75.0;height = 15; break;
              
               //transform.position.x=Mathf.Lerp(heightArray[3],heightArray[3],Time.time);Debug.Log("case3");break;  
               i= 3;transform.position.x=Mathf.Lerp(distanceArray[3],distanceArray[3],Time.time*speed);Debug.Log("case3Lngth");break;
         case 2:
              
               //transform.position.x=Mathf.Lerp(heightArray[2],heightArray[3],Time.time);Debug.Log("case2");break;  
               i=2;transform.position.x=Mathf.Lerp(distanceArray[2],distanceArray[3],Time.time*speed);Debug.Log("case2Lngth");break;  
        
         case 1:
              
               //transform.position.x=Mathf.Lerp(heightArray[1],heightArray[2],Time.time);Debug.Log("case1");break;  
               i=1;transform.position.x=Mathf.Lerp(distanceArray[1],distanceArray[2],Time.time*speed);Debug.Log("case1Lngth");break;
        
         case 0:                                                                                        
              
               //transform.position.x=Mathf.Lerp(distanceArray[0],distanceArray[1],Time.time);Debug.Log("case0");break;  
               //transform.position.z=Mathf.Lerp(lengthArray[0],lengthArray[1],Time.time);Debug.Log("case0Lngth");break;
               i= 0;transform.position.x=Mathf.Lerp(heightArray[0],heightArray[1],Time.time*speed);Debug.Log("case0Lngth");break;
         }
    
    
    
    
     currentRotationAngle = Mathf.LerpAngle(currentRotationAngle,wantedRotationAngle,rotationDamping*Time.deltaTime);
     var currentRotation = Quaternion.Euler(0,currentRotationAngle,0);
     transform.position = target.position;
     transform.position -= currentRotation*Vector3.forward*distance;
     transform.position.y = wantedHeight;
     transform.LookAt (target);
 }