More Effective Camera Switching

For a Video Game Design class project, I have been working on a simple solar system. It has all of the planets rotating around the the sun, etc. I wanted to create a GUI element where you could click on a button with the name of the planet (ex: button says "Earth"), and the camera would switch to follow that planet's orbit. I read up on the scripting reference, and I came up with something that worked after much forum browsing/trial and error (I am pretty new to scripting). I was wondering if someone could show me a more efficient way to do this. First, I'll show the way I came up with.

BasicalIy, my method was to make a camera for each planet, and attach this script to each:

 #pragma strict
 var target : Transform;
 
 
 function Update () {
     transform.LookAt(target);
 
 }

That one makes the camera look at its designated planet. The other script was for the GUI:

 #pragma strict
 
 var mainview : Camera;
 var marsview : Camera;
 var earthview : Camera;
 var mercuryview : Camera;
 var jupiterview : Camera;
 var plutoview : Camera;
 //states variables of the cameras
 
 function Start () {
     //deactivates all cameras but the main camera
     mainview.camera.active = true;
     marsview.camera.active = false;
     earthview.camera.active = false;
     mercuryview.camera.active = false;
     jupiterview.camera.active = false;
     
 }
 
 
 function OnGUI () {
     //creates GUI
     GUI.Box (Rect (0, 10, 200, 90), "Camera View Switch");
     if (GUI.Button (Rect (20, 40, 80, 20), "Earth")) { //first button
         mainview.camera.active = false;
         marsview.camera.active = false;
         mercuryview.camera.active = false;
         jupiterview.camera.active = false;
         earthview.camera.active = true;
         //activates earthview camera, deactivates all others
     }    
     if (GUI.Button (Rect (20, 70, 80, 20), "Mars")) {
            mainview.camera.active = false;
         earthview.camera.active = false;
         mercuryview.camera.active = false;
         jupiterview.camera.active = false;
         marsview.camera.active = true;
     }
     if (GUI.Button (Rect (20, 100, 80, 20), "Sun")) {
         earthview.camera.active = false;
         marsview.camera.active = false;
         mercuryview.camera.active = false;
         jupiterview.camera.active = false;
         mainview.camera.active = true;
     }
     if (GUI.Button (Rect (20, 130, 80, 20), "Mercury")) {
         earthview.camera.active = false;
         marsview.camera.active = false;
         mainview.camera.active = false;
         jupiterview.camera.active = false;
         mercuryview.camera.active = true;
     }
     if (GUI.Button (Rect (20, 160, 80, 20), "Jupiter")) {
         earthview.camera.active = false;
         marsview.camera.active = false;
         mainview.camera.active = false;
         mercuryview.camera.active = false;
         jupiterview.camera.active = true;
     }
     if (GUI.Button (Rect (20, 190, 80, 20), "Pluto")) {
         earthview.camera.active = false;
         marsview.camera.active = false;
         mainview.camera.active = false;
         mercuryview.camera.active = false;
         jupiterview.camera.active = false;
         plutoview.camera.active = true;
     }
 
 }
 
 function Update () {
 
 }

I didn't include all of the planets for the sake of example, but you get the idea. Being pretty new to this, I was glad I could find a solution that worked. Now I am looking for community input. If it isn't too much trouble, could someone show me a better, more efficient/effective way to accomplish this?