Not Sure How to Get Around this Problem

I'm trying to make 1 object go towards another using Lerp on the X axis. I'm not completely sure but I think the problem is Lerp is a Vector3 but I'm trying to access the X position of the target variable(can someone correct me if I'm wrong?), because if I take out the .x part of my script I get no errors. Here is my script what am I doing wrong?

var target : Transform;

function Update(){
    transform.position = Vector3.Lerp(transform.position, target.position.x, Time.time * 0.001);

}

If you're just concerned about the X axis, don't bother with Y and Z.

transform.position.x = Mathf.Lerp(transform.position.x, target.position.x, Time.time * 0.001);