function init()

{

document.getElementById("balao").onmouseover = function(){document.getElementById("sub_menu").style.display='block';};
document.getElementById("balao").onmouseout = function(){document.getElementById("sub_menu").style.display='none';};
document.getElementById("sub_menu").onmouseout = function(){document.getElementById("sub_menu").style.display='none';};
document.getElementById("sub_menu").onmouseover = function(){document.getElementById("sub_menu").style.display='block';};

document.getElementById("balao2").onmouseover = function(){document.getElementById("sub_menu2").style.display='block';};
document.getElementById("balao2").onmouseout = function(){document.getElementById("sub_menu2").style.display='none';};
document.getElementById("sub_menu2").onmouseout = function(){document.getElementById("sub_menu2").style.display='none';};
document.getElementById("sub_menu2").onmouseover = function(){document.getElementById("sub_menu2").style.display='block';};

document.getElementById("balao3").onmouseover = function(){document.getElementById("sub_menu3").style.display='block';};
document.getElementById("balao3").onmouseout = function(){document.getElementById("sub_menu3").style.display='none';};
document.getElementById("sub_menu3").onmouseout = function(){document.getElementById("sub_menu3").style.display='none';};
document.getElementById("sub_menu3").onmouseover = function(){document.getElementById("sub_menu3").style.display='block';};

}

 window.onload=init