function ReklamaOn(szerokosc,wysokosc)
{
  elem = document.getElementById("overlayreklama");
  elem.style.height = document.body.offsetHeight +'px';
  
  
    var theWidth, theHeight;
    // Window dimensions:
    theWidth = 700;
    theHeight = 500;
    if (window.innerWidth) {
    theWidth=window.innerWidth;
    }
    else if (document.documentElement && document.documentElement.clientWidth) {
    theWidth=document.documentElement.clientWidth;
    }
    else if (document.body) {
    theWidth=document.body.clientWidth;
    }
    if (window.innerHeight) {
    theHeight=window.innerHeight;
    }
    else if (document.documentElement && document.documentElement.clientHeight) {
    theHeight=document.documentElement.clientHeight;
    }
    else if (document.body) {
    theHeight=document.body.clientHeight;
    }  
  
  gora = (theHeight-wysokosc)/2;
  lewo = (theWidth-szerokosc)/2;
  elem = document.getElementById("reklama");
  elem.style.top = gora+'px';
  elem.style.left = lewo+'px';
}

function ReklamaOff()
{
 
 elem = document.getElementById("overlayreklama");
 elem.style.display = 'none';
 elem = document.getElementById("reklama");
 elem.style.display = 'none';
}