function show_menu()
  {
	 thelement=document.getElementById? document.getElementById("roll_menu"): document.all.roll_menu 
	 thelement.style.display = "block";
	}

 function hide_menu()
  {
	 thelement=document.getElementById? document.getElementById("roll_menu"): document.all.roll_menu
	 thelement.style.display = "none";
	}

 function highlight(menu_item)
  {
	 thelement=document.getElementById? document.getElementById(menu_item): document.all.menu_item
	 thelement.style.background = "009999";
	}
	
 function nolight(menu_item)
  {
	 thelement=document.getElementById? document.getElementById(menu_item): document.all.menu_item
	 thelement.style.background = "transparent";
	}
	
 function new_window(file_name,sirka,vyska)
  {
   path = "./samples/"+file_name;
	 window.open(path,"sample","toolbar=no,location=no,status=no,menubar=no,scrollbars=no,resizable=no,width="+sirka+",height="+vyska+",top=20,left=100");
	}