/*function used to hover image on mouseover*/ 
function rollover(img_name, img_src){
       document[img_name].src = img_src;
}

function rolloverArrow(img_name, img_src,isDisplay){
       document[img_name].src = img_src;
	   if(isDisplay=="true")
	   {
		   document.getElementById("arrow-top-head").style.display = "block";	   
	   }
	   else
	   {
		   document.getElementById("arrow-top-head").style.display = "none";		   
	   }

}