3d gameobject positioning on screen screen resolution

Hello,

I have a 3d gameobject attached to the camera (healhtbar)

http://i1086.photobucket.com/albums/j460/EmoUtd/Random%20pics/healthbar.jpg

what i am baffled about is how to i position this object depending on the screen height/width

i have these sets of codes, but baffled from how I take it from here

 private GameObject hbar;
 private float sWid = Screen.width;
 private float sHei = Screen.height;
 private Vector3 screen;

void Update () {

     hbar=GameObject.FindWithTag ("hbar");
     screen = Camera.main.WorldToScreenPoint(hbar.transform.position);
     
 }