function dimensionOverlayer() {

 var tmpWidth  = loadDimension()[0];
 var tmpHeight = loadDimension()[1]; 

 if($('overlay') && Number(tmpWidth) && Number(tmpHeight)) {
  $('overlay').setStyle( { width: tmpWidth + 'px', height: tmpHeight + 'px' } );
  return true;
 }
  
}

function loadOverlayer() {
 $('overlay').appear({ duration: 0.8, from: 0, to: 0.4 });
// $('advertising_footer').hide();
 return true;
}

function unloadOverlayer() {
 $('overlay').fade({ duration: 0.4, from: 0.4 });
// $('advertising_footer').show();
 Event.stopObserving('overlay', 'click');
 return true;
}






function positionOverlayerElement(sendId) {

	 var arrayPageScroll 	= document.viewport.getScrollOffsets(); 
	 var dateTop 		= arrayPageScroll[1] + (document.viewport.getHeight() / 10);
	 
	 $(sendId).setStyle( { top: dateTop + 'px' } );

}






function loadDimension() {
	        
	     var xScroll, yScroll;
		
		if (window.innerHeight && window.scrollMaxY) {	
			xScroll = window.innerWidth + window.scrollMaxX;
			yScroll = window.innerHeight + window.scrollMaxY;
		} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
			xScroll = document.body.scrollWidth;
			yScroll = document.body.scrollHeight;
		} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
			xScroll = document.body.offsetWidth;
			yScroll = document.body.offsetHeight;
		}
		
		var windowWidth, windowHeight;
		
		if (self.innerHeight) {	// all except Explorer
			if(document.documentElement.clientWidth){
				windowWidth = document.documentElement.clientWidth; 
			} else {
				windowWidth = self.innerWidth;
			}
			windowHeight = self.innerHeight;
		} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
			windowWidth = document.documentElement.clientWidth;
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body) { // other Explorers
			windowWidth = document.body.clientWidth;
			windowHeight = document.body.clientHeight;
		}	
		
		// for small pages with total height less then height of the viewport
		if(yScroll < windowHeight){
			pageHeight = windowHeight;
		} else { 
			pageHeight = yScroll;
		}
	
		// for small pages with total width less then width of the viewport
		if(xScroll < windowWidth){	
			pageWidth = xScroll;		
		} else {
			pageWidth = windowWidth;
		}


 return [pageWidth,pageHeight];
}