Question about distance between 2 objects

This is pretty much newbie question.

I am measuring the distance between two objects with the script below. Anyway, how can I measure the distance only in the x and z axis? Basically, I would like to omit the altitude of objects when measuring the distance between them. Is there any simple way to do this?

Code (csharp):

1. var distance: float;
2. var A : GameObject;
3. var B : GameObject;
4.  
5. function Update () {
6.  
7. // calculate distance between A and B
8.    
9. distance = Vector3.Distance(A.transform.position, B.transform.position);
10.        
11. }

 

Code (csharp):

1.  
2. Vector3 p1 = A.transform.position;
3. Vector3 p2 = B.transform.position;
4. p1.y = p2.y;
5.  
6. distance = (p1-p2).magnitude;
7.  

 

Thanks for offering to help me menneske! Anyway, I ran to some problems when testing the script. Below is the script like I have it right now. Do you have idea what is causing the problem?

According to Unity:
Assets/Scripts/NewBehaviourScript.js(9,8 ): UCE0001: ';' expected. Insert a semicolon at the end.

I inserted the semicolons but then Unity claims:
Assets/Scripts/NewBehaviourScript.js(9,1): BCE0034: Expressions in statements must only be executed for their side-effects.

Code (csharp):

1. var distance: float;
2. var A : GameObject;
3. var B : GameObject;
4.  
5. function Update () {
6.  
7. // calculate distance between A and B
8.    
9. Vector3 p1 = A.transform.position;
10. Vector3 p2 = B.transform.position;
11. p1.y = p2.y;
12.  
13. distance = (p1-p2).magnitude;
14.        
15. }

 

Yeah, sorry, the code I posted is C#, not JavaScript. The javascript would look like this:

Code (csharp):

1.  
2. var p1 : Vector3 = A.transform.position;
3. var p2 : Vector3 = B.transform.position;
4. p1.y = p2.y;
5.  
6. distance = (p1-p2).magnitude;
7.  

 

Thanks again!