Mouse drag on X, Z axes?

Hi all, i'm newie on js scripting. I try to apply script in to game object to move on 2d X and Z axes.
For to do that y follow a flasdevelop tutorial with this example code:

Code (csharp):

1.  
2. function Update () {
3. }
4.  
5. var screenSpace;
6. var offset;
7.  
8. function OnMouseDown(){
9.     //translate the cubes position from the world to Screen Point
10.     screenSpace = Camera.main.WorldToScreenPoint(transform.position);
11.      
12.     //calculate any difference between the cubes world position and the mouses Screen position converted to a world point  
13.     offset = transform.position - Camera.main.ScreenToWorldPoint(Vector3(Input.mousePosition.x,Input.mousePosition.y, screenSpace.z));
14.    
15. }
16.  
17. /*
18. OnMouseDrag is called when the user has clicked on a GUIElement or Collider and is still holding down the mouse.
19. OnMouseDrag is called every frame while the mouse is down.
20. */
21.  
22. function OnMouseDrag () {
23.  
24.     //keep track of the mouse position
25.     var curScreenSpace = Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z);    
26.  
27.     //convert the screen mouse position to world point and adjust with offset
28.     var curPosition = Camera.main.ScreenToWorldPoint(curScreenSpace) + offset;
29.  
30.     //update the position of the object in the world
31.     transform.position = curPosition;
32.      
33. }
34.  

The code only move my object on X,Y axes :S.

How can i modify this code to move with drag mouse on X and Z axes?

Thanks
Sorry my bad english.

 

Hello!

I think your problem resides here

Code (csharp):

1. var curScreenSpace = Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z);