how OnTriggerStay Have a time

Please help if the gameobject stay thre at 3 secont the GUI will appear thx

here is the Code

void OnTriggerStay(Collider collision)
{

bShoGUI = false;

}

if the timer is = 3 secont the GUI will appear thx Im new to Unity3d

Try this:

   float  t = 0;

   void OnTriggerEnter(Collider other) 
   {
      t = 0;
   }

   void OnTriggerStay(Collider other)
   {
        t += Time.deltaTime;
        if(t > 3) {
           //Do something
        }
   }