cursor change on play

how do i change the mouse pointer/cursor when i play my game?

This is what I use - and it works fine:

var myCursor:Texture2D;
var cursorSizeX: int = 32;  // set to width of your cursor texture
var cursorSizeY: int = 32;  // set to height of your cursor texture

function Start(){
Screen.showCursor = false;
}

function OnGUI(){
    GUI.DrawTexture (Rect(Input.mousePosition.x-cursorSizeX/2 + cursorSizeX/2, (Screen.height-Input.mousePosition.y)-cursorSizeY/2 + cursorSizeY/2, cursorSizeX, cursorSizeY),myCursor);
}

You can hide the system cursor using (IIRC) Screen.showCursor. As for replacing it with a custom cursor, there are various ways this can be done, but a common solution is to render a texture at the mouse position using the built-in GUI system.

For more info, search here or on the forums for 'custom cursor' (this question has been asked numerous times before).

What do I put in the Texture2D part?