On Mouse Down Load Previous

[sketchers1]

I wanted to use function OnMouseDown(){} to load the last level that was open, and I cant find anywhere that shows how to do that? Can someone help? Thanks in advance…
EDIT:

I have this script for loading last played level on awake, but i cant figure out the script to attach to a box collider that I want to click to load the last level:

//LevelLoadManager.js
private var currentLevel:int = -1;

function Awake():void
{
    //retrieve and load last level played.
    DontDestroyOnLoad(gameObject);
    currentLevel = PlayerPrefs.GetInt("LastLevelLoaded");
    Application.LoadLevel(currentLevel);
}

function Update():void
{
    //save the current level if it seems to have changed.
    if(Application.loadedLevel != currentLevel)
    {
        currentLevel = Application.loadedLevel;
        PlayerPrefs.SetInt("LastLevelLoaded",currentLevel);

}
}

[Sundar]

use PlayerPrefs to store current level as previouslevel when you go to next level.

Then call previouslevel OnMouseDown(){}

[Seth-Bergman]

instead of Awake, make it a unique function:

function LoadLastLevel()
{
    //retrieve and load last level played.
    DontDestroyOnLoad(gameObject);
    currentLevel = PlayerPrefs.GetInt("LastLevelLoaded");
    Application.LoadLevel(currentLevel);
}

then on the cube:

var gameLoader : LevelLoadManager;

function Start(){
gameLoader = GameObject.Find("LoaderObjectName").GetComponent(LevelLoadManager);
}

function OnMouseDown(){
gameLoader.LoadLastLevel();    
}