Set boolean to true from another scene

Hello guys I’m making an unlocking level system for my game.
I want that when the player enters on a onTrigger sets the value to true of l1unlocked.
Here is the script

#pragma strict
var l1unlocked = false;
var unlockedt = Texture2D;
var lockedt = Texture2D;

if (l1unlocked == false)
renderer.material.mainTexture  = lockedt;
} else { 
    renderer.material.mainTexture  = unlockedt;
}
function OnMouseUp(){ //only if level is unloked if is locked can't load level
Application.LoadLevel(2);
}

I also want to load the scene only if the level 1 is unlocked.
I need a script that sets the l1unlocked to true using the function OnCollisionEnter and makes the scene loadable.

You can use static variables which are shared between scenes.