I don't know why I can't use ,,Vote Up" button...BUT THANKS! I'TS WORK AND HELPED ME A LOT! THANK YOU!

//Inactive Objects script
//Inactive obj has isTrigger Collider attached

public var myMenu:MyMenu;

function OnTriggerEnter(other:Collider)
{
    if(other.CompareTag("Player"))
    {
        myMenu=other.GetComponent(MyMenu);
        myMenu.showActivateButton=true;
        myMenu.objectToActivate=gameObject;
    }
}
function OnTriggerExit(other:Collider)
{
    if(other.CompareTag("Player"))
    {
        myMenu.showActivateButton=false;
    }
}

//MyMenu.js

public var objectToActivate:GameObject;
public var showActivateButton:boolean;

function OnGUI()
{
    if(showActivateButton)
    {
        if(GUI.Button(myRect,"Activate Object")
        {
            objectToActivate.active=true;
            showActivateButton=false;
        }
    }
}

This relies on: MyMenu.js is a component on the player, the trigger is on the inactive object, player is tagged as "Player",