function showdropdown()
{
var comsty;

    if(document.layers) comsty = document.dropdown;
    else if(document.getElementById && !document.all) comsty = document.getElementById("dropdown").style;
    else if(document.all) comsty = document.all.dropdown.style;
	
comsty.visibility='visible';
}

function hidedropdown()
{
var comsty;

    if(document.layers) comsty = document.dropdown;
    else if(document.getElementById && !document.all) comsty = document.getElementById("dropdown").style;
    else if(document.all) comsty = document.all.dropdown.style;
	
comsty.visibility='hidden';
}