simply move an an object

Can someone give me a script that lets me move a simple cube up and down just to see if the camera works in 2d motion?

Create a new script below, and drop it in your cube. Press play and the cube will move up and down using the awsd or up and down arrow keys (unless you changed the ide's default keyset)

function Update () {
   transform.Translate(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical"),0);
}

For further explanations, you might want to look @ http://docwiki.unity3d.com/uploads/Main/Scripting%20Tutorial.pdf