How to alter input to continuous rather than tap?

My code works perfectly in rotating a cube around both axis’ (axees?)
My problem is that you have to continuously tap a key to get it to move in the desired direction, how do I make it so that holding the key down moves it in that direction continuously, rather than just once, and at the same speed.

Code:

var speed = 5000;

function Update () 
{
	if(Input.GetKeyDown("left")){
        transform.Rotate(0, 0, Input.GetAxis("Horizontal") * speed * Time.deltaTime,Space.World);;
    }

Also, that “var speed = 5000” doesn’t actually seem to be changing anything, thats why it’s at such an insanely high number. How do i speed up the rotation?

GetKeyDown() is only true for one frame. If you want to hold the button down, use GetKey().

Also don’t post the same question multiple times. Sometimes it can take a bit until a new question is published by a mod. Please be patient if a question doesn’t appear immediately.