Code please, im having a hard time understanding what you mean.

You could just make an if-sentence stating that if raycast 2 is null, then it should use raycast 1.

Edit:

private GameObject hGO;
private GameObject h2GO;

void Update () {
    RaycastHit hit;
    RaycastHit hit2;

    //cast the first ray, this one goes down
    if(Physics.Raycast(transform.position, -Vector3.up, out hit, 100f)){
       hGO = hit.collider.gameObject;
    }else{
       hGO = null;
    }

    //cast the second ray, this one goes up
    if(Physics.Raycast(transform.position, Vector3.up, out hit2, 100f)){
       h2GO = hit2.collider.gameObject;
    }else{
       h2GO = null;
    }


    //prioritize between the different controls
    if(h2GO != null)
    {
       Debug.Log("using set two");
    }
    else if(hGO != null)
    {
       Debug.Log("using set one");
    }
    else
    {
       Debug.Log("using something else");
    }
 }

this would have worked if you had only had 3 controls, you should be able to adapt it into 4 controls if you play around with it for a bit. playing around with as many bools as you've got is just silly :P

I wanted to keep things simple with the question, there are actually 4 raycasts :p

    private var myFloor : boolean = true;   
    private var myCeling : boolean = false;
    private var myLeftwall : boolean = false;
    private var myRightwall : boolean = false;

    var myLine : float = 1.5;

    var moveSpeed : float = 1.0;
    var height : float = 10.0;

    var gravity : float = 100.0;

function Update () {
    //Raycast for floor contrls
    var up = transform.TransformDirection(Vector3.up);
    Debug.DrawRay(transform.position, -up * myLine, Color.green);
if(Physics.Raycast(transform.position, -up, myLine)){
    myFloor = true;
    myCeling = false;
    myLeftwall = false;
    myRightwall = false;

    Debug.Log("Floor");

    //rigidbody.velocity = Vector3(0, 0, 0);
    //rigidbody.AddForce(Vector3(0, -gravity, 0));
}
    //Raycast for celing controls
    var down = transform.TransformDirection(Vector3.up);
    Debug.DrawRay(transform.position, down * myLine, Color.green);
if(Physics.Raycast(transform.position, down, myLine)){   
    Debug.Log("Celing");
    myCeling = true;
    myFloor = false;
    myLeftwall = false;
    myRightwall = false;

    //rigidbody.velocity = Vector3(0, 0, 0);
    //rigidbody.AddForce(Vector3(0, gravity, 0));

    }

    //Raycast for left wall controls
    var myLeft = -transform.TransformDirection(Vector3.right);
if(Physics.Raycast(transform.position, myLeft, myLine)){       
    Debug.Log("LeftWall");
    myLeftwall = true;
    myFloor = false;
    myCeling = false;
    myRightwall = false;

//rigidbody.velocity = Vector3(0, 0, 0);
//rigidbody.AddForce(Vector3(-gravity, 0, 0));
}
    //Raycast for right wall controls
    var myRight = transform.TransformDirection(Vector3.right);
if(Physics.Raycast(transform.position, myRight, myLine)){     
    Debug.Log("RightWall");
    myRightwall = true;
    myFloor = false;
    myCeling = false;
    myLeftwall = false;

    //rigidbody.velocity = Vector3(0, 0, 0);
    //rigidbody.AddForce(Vector3(gravity, 0, 0));
    }

    //Floor controls
    if(myFloor == true){

       if(Input.GetButton("right"))
    {
         transform.position += transform.right *moveSpeed* Time.deltaTime;
    }
       if(Input.GetButton("left"))
    {
         transform.position += -transform.right *moveSpeed* Time.deltaTime; 
    }
       if(Input.GetButton("jump"))
    {
         transform.position += transform.up *height* Time.deltaTime; 
    }

         }

    //Celing controls   
    if(myCeling == true){

       if(Input.GetButton("right"))
    {
         transform.position += transform.right *moveSpeed* Time.deltaTime;
    }
       if(Input.GetButton("left"))
    {
         transform.position += -transform.right *moveSpeed* Time.deltaTime; 
    }
       if(Input.GetButton("jump"))
    {
         transform.position += -transform.up *height* Time.deltaTime; 
    }

        }

    //Left Wall controls
    if(myLeftwall == true){

       if(Input.GetButton("up"))
    {
         transform.position += transform.up *moveSpeed* Time.deltaTime;
    }
       if(Input.GetButton("down"))
    {
         transform.position += -transform.up *moveSpeed* Time.deltaTime; 
    }
       if(Input.GetButton("jump"))
    {
         transform.position += -transform.right *height* Time.deltaTime; 
    }

         }


    if(myRightwall == true){   

       if(Input.GetButton("up"))
    {
         transform.position += transform.up *moveSpeed* Time.deltaTime;
    }
       if(Input.GetButton("down"))
    {
         transform.position += -transform.up *moveSpeed* Time.deltaTime; 
    }
       if(Input.GetButton("jump"))
    {
         transform.position += transform.right *height* Time.deltaTime; 
    }

    }
       }