function showDropDown (menuid)
{
	clearDropDowns ();
	var dd = document.getElementById(menuid);
	dd.style.display = "block";
}

function hideDropDown (menuid)
{
	var dd = document.getElementById(menuid);
	dd.style.display = "none";
}

function clearDropDowns ()
{
	for (i = 0; i < dropDowns.length; i ++)
	{
		hideDropDown(dropDowns[i]);
	}
}