Unity 4.0 mesh duplication possible?

I need a code to duplicate mesh without original mesh disappearing. is it possible? how?

Update: Full Code

 #pragma strict
 
 var Test : Transform;
 
 var Nyil : Transform;
 var NyilStorage = new Array();
 
 var hit : RaycastHit;
 var curhit : RaycastHit;
 
 var hSliderOldValue : int[] = new int[10] ;
 var hSliderValue : int[] = new int[10] ;
 
 var Vertices : Vector3[];
 
 private var a = new Array("Models","Morph","Vertices");
 private var b = new Array("Number");
 private var c = new Array("Id","Mod","DirX" ,"DirY" ,"DirZ","Target");
 var LD : String[,,] = new String[0,0,0];
 
 var MousePos : Vector2;
 var ScreenPosV : Vector2;
 var SelNyil : int;
 
 function Start () {
     XML.OpenXML("Modules/" + "Modul"  );
     LD = XML.ReadXMLAdv(a,b,c);
     TestNewObj();
     
 }
 
 function Update () {
     
     SelectObject();
 }
 
 
 function OnGUI(){
 //print(hit.collider);
     if (GUI.Button(Rect(0,0,50,20),"press") ){
         Vertices = (hit.collider as MeshCollider).sharedMesh.vertices; 
         print((hit.collider as MeshCollider).sharedMesh.vertices[0]);
         for(var i = 1;i<LD.GetLength(1);i++){
             Vertices[ parseInt(LD[0,i,0]) ] = Vertices[ parseInt(LD[0,i,0]) ] + Vector3.up ;
             print(i);
             
         }
         (hit.collider as MeshCollider).sharedMesh.vertices = Vertices;
     }
 
     MorphSlider();
     
     if (GUI.changed){
         for(i = 0;i<hSliderValue.length;i++){
             if(hSliderOldValue[i] != hSliderValue[i]){
                 
                 hSliderOldValue[i] = hSliderValue[i];
                 NyilRePos(i);
                 //print("Changed " + i);
             }        
         }
     }
         
 
 
 }
 
 function SelectObject(){
 
     if(Input.GetMouseButtonUp(0)){
         if (Physics.Raycast (camera.ScreenPointToRay(Input.mousePosition), curhit)){
 //        print(curhit.collider.name + "  " + (curhit.collider as MeshCollider).sharedMesh );
             if (curhit.collider != null || (curhit.collider as MeshCollider).sharedMesh != null ){ 
                 if(hit.collider != curhit.collider && curhit.collider.name != "Arrow(Clone)"){
                     hit=curhit;
                     NyilDestroy();
                     NyilInit();
                     
                 }
                             
             }
         }
     }
     if(Input.GetMouseButton(0)){
     if(Input.GetMouseButtonDown(0)){
     SelNyil = -1;
         if (Physics.Raycast (camera.ScreenPointToRay(Input.mousePosition), curhit)){
         
         print("ar");
             if( curhit.collider.name == "Arrow(Clone)"){
                  var screenPosA : Vector3 = camera.WorldToScreenPoint (curhit.transform.position);
                  var screenPosB : Vector3 = camera.WorldToScreenPoint (hit.transform.position);
                  ScreenPosV = (Vector2( screenPosA.x,screenPosA.y ) - Vector2( screenPosB.x, screenPosB.y )).normalized ;
                  MousePos = Vector2(Input.mousePosition.x,Input.mousePosition.y) ;
                  SelNyil = (curhit.transform.GetComponent("Destroy") as Destroy).Count ;
                 //print(ScreenPosV + "  mp: " + MousePos);
                 //print("a");
             }
                 
         }}        
 //        print(SelNyil);
         if(SelNyil != -1){
             var MousePosCurr : Vector2 = Vector2(Input.mousePosition.x,Input.mousePosition.y) ;
             var NewSliderPos : int = hSliderOldValue[SelNyil] + Mathf.CeilToInt( ((MousePosCurr.x - MousePos.x) /30 * ScreenPosV.x ) + ( (MousePosCurr.y - MousePos.y) /30 * ScreenPosV.y) );
             hSliderValue[SelNyil] = (NewSliderPos < 0) ? 0 : NewSliderPos ;
             NyilRePos(SelNyil);
             
         }
     }
     if(Input.GetMouseButtonUp(0)){
         if(SelNyil != -1){
             hSliderOldValue[SelNyil] = hSliderValue[SelNyil];
         }
     }
 }
 
 
 function MorphSlider(){
 
     for( var i = 0;i<LD.GetLength(0) ;i++){
         hSliderValue[i] = GUI.HorizontalSlider(Rect(0,0 + i*22,80,20), hSliderValue[i], 0, 10 );
         GUI.Label(Rect(85,0 +i*22,80,20),hSliderValue[i] + "  Morph"+ i.ToString() );
     }
 
 
 }
 
 function NyilInit(){
 
     for(var i =0;i<LD.GetLength(0);i++){
         var pos = Vector3( parseInt(LD[i,0,2]) , parseInt(LD[i,0,3]) , parseInt(LD[i,0,4]) );
         NyilStorage.Add( Instantiate(Nyil,hit.collider.transform.position + pos, Quaternion.LookRotation(pos*-1 )) );
         ((NyilStorage[NyilStorage.length-1] as Transform).GetComponent("Destroy") as Destroy).SetCount(i);
     }
 
 }
 
 function NyilDestroy(){
 
      for (var value : Transform in NyilStorage) {
          (value.GetComponent("Destroy") as Destroy).SelfDestroy();
      }
      NyilStorage.Clear();
 
 }
 
 function NyilRePos(i){
     //print("value " + i +"pos: " + Vector3( parseInt(LD[i,0,2]) , parseInt(LD[i,0,3]) , parseInt(LD[i,0,4])) * (hSliderOldValue[i]+1) );
     (NyilStorage[i] as Transform).position = hit.collider.transform.position + Vector3( parseInt(LD[i,0,2]) , parseInt(LD[i,0,3]) , parseInt(LD[i,0,4])) * (hSliderValue[i]+1);
 
 }
 
 function TestNewObj(){
     
     
      var m = new Mesh();
      m.name = "Scripted_Plane_New_Mesh";
      
      // var MeshSource : Mesh = Test.GetComponent(MeshFilter).mesh;
     
      /* 
      var ver : Vector3[] = Test.GetComponent(MeshFilter).mesh.vertices;
      var tri : int[] = Test.GetComponent(MeshFilter).mesh.triangles;
      var uv : Vector2[] = Test.GetComponent(MeshFilter).mesh.uv;
      var norm : Vector3[] = Test.GetComponent(MeshFilter).mesh.normals;
      
      m.vertices = ver;
      m.triangles = tri;
      m.uv = uv;
      m.normals = norm;
     */
     
      var obj : GameObject = new GameObject("New_Plane_Fom_Script", MeshRenderer, MeshFilter, MeshCollider);
         
      obj.GetComponent(MeshFilter).mesh = Instantiate(Test.GetComponent(MeshFilter).mesh);//m;
      obj.GetComponent(MeshCollider).mesh = Instantiate(Test.GetComponent(MeshFilter).mesh);// m;
      obj.GetComponent("Renderer").renderer.material = Resources.Load("Materials/Default2") as Material;
 
 //    MeshFilter mf = GetComponent<MeshFilter>();
 //    mf.mesh = (Mesh)Instantiate(mf.mesh);
     
 }