function showdiv(menu,x,y){hidediv();document.getElementById(menu).style.left=x+'px';document.getElementById(menu).style.top=y+'px';document.getElementById(menu).style.visibility='visible';}
function hidediv(){document.getElementById("menu1").style.visibility='hidden';document.getElementById("menu2").style.visibility='hidden';document.getElementById("menu3").style.visibility='hidden';document.getElementById("menu4").style.visibility='hidden';}
function toggle_visibility(id){var e=document.getElementById(id);if(e.style.display=='block')
e.style.display='none';else
e.style.display='block';}