Loss of gravity and interation with box collider

[anon32696899]

I'm pretty much brand new to scripting, but I have been using Unity as a way to help me learn, I find having a visual result of my efforts makes retaining information easier.

Anyway I am attempting to create a basic character that will move along the x axis and I seem to have accomplished that, but somewhere along the line I have lost the characters ability to fall and interact with the object below it that has a box collider. Below is the script i am working with, can anyone see where i have gone wrong?

var speed = 1.0;

//This works fine, but lacks gravity.

function Update () {
    //var xPos = Input.GetAxis("Horizontal") * Time.deltaTime * speed; ...This is defunct script - ignore.
    var controller : CharacterController = GetComponent(CharacterController);

    var right =transform.TransformDirection(Vector3.forward);

    var xPos = Input.GetAxis("Horizontal") * Time.deltaTime * speed;
    controller.SimpleMove(right * xPos);

//The below line allows the character to move, however it also prevents 
//the character from falling onto the ground and staying there, he floats 
//through the air when no geomentry is immediately below him, slowly 
//succombing to the effects of gravity that are affected through the above lines, why?

    transform.position.x += xPos;

    var move = Vector3(xPos, 0.0, 0.0);
    if (move != Vector3.zero) {
        var rotation = transform.rotation; 
        rotation.SetLookRotation(move); 
        transform.rotation = rotation;
    }
}

Only problem is now is that when my little guy runs up a hill when he turns to run back down it he instead floats along the x axis and slowly goes back down to the ground cube i have... Can i increase the gravity of my little guy?

Update - Tried suggestion, did not work, but through experimentation I have narrowed it down to transform.position.x += xPos ...I think it's that little ".x" that is causing the problem, but I don't know how to rephrase it without losing the movement of the character along the x axis.

[anon72047421]

add a rigidbody to it and it will get the effect your after. or add something like `moveDirection.y -= gravity * (Time.deltaTime/2);`