editor script makes editor crash

i'm trying to make an editor script that will take a heightmap and turn it in to a cubic terrain but when i run the script the editor crashes.

 #pragma strict
 class CubeLand extends EditorWindow{
     
     var texture:Texture2D;
     var index:int = 0;
     var options:String[] = ["full", "half", "quarter"];
     var obj:GameObject;
     var size:Vector3;
     
     @MenuItem ("Window/CubeLand")
     
     static function ShowWindow(){
         EditorWindow.GetWindow (CubeLand);
     }
     
     function OnGUI () {
         texture = EditorGUI.ObjectField(Rect(3, 3, Screen.width, 100), "HeightMap", texture, Texture, false);
         index = EditorGUI.Popup(Rect(3, 106, Screen.width, 50), "Resolution: ", index, options);
         if(index == 0){
             //if full res
             if(GUI.Button(Rect(0, Screen.height - Screen.height/10, Screen.width, Screen.height/10), "Generate")){
                 for(var x:int = 0; x < texture.height; x++){
                     for(var z:int = 0; z < texture.width; z++){
                         obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
                         obj.transform.position = Vector3(x, 0, z);
                         obj.transform.position.y = Mathf.RoundToInt(texture.GetPixel(x, z).grayscale * 15);
                     }
                 }
             }
         }else if(index == 1){
             //if half res
             if(GUI.Button(Rect(0, Screen.height - Screen.height/10, Screen.width, Screen.height/10), "Generate")){
                 for(var x2:int = 0; x2 < texture.height/2; x2++){
                     for(var z2:int = 0; z2 < texture.width/2; z2++){
                         obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
                         obj.transform.position = Vector3(x2, 0, z2);
                         obj.transform.position.y = Mathf.RoundToInt(texture.GetPixel(x, z).grayscale * 15);
                     }
                 }
             }
         }else if(index == 2){
             //if quarter res
             if(GUI.Button(Rect(0, Screen.height - Screen.height/10, Screen.width, Screen.height/10), "Generate")){
                 for(var x3:int = 0; x3 < texture.height/4; x3++){
                     for(var z3:int = 0; z3 < texture.width/4; z3++){
                         obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
                         obj.transform.position = Vector3(x3, 0, z3);
                         obj.transform.position.y = Mathf.RoundToInt(texture.GetPixel(x, z).grayscale * 15);
                     }
                 }
             }
         }
     }
 }