function hideAllSelects()
{
    for (var formIndex=0;formIndex < document.forms.length;formIndex++) {
        for (var elementIndex=0;elementIndex < document.forms[formIndex].elements.length;elementIndex++) {
            if(document.forms[formIndex].elements[elementIndex].type.substr(0,6) == 'select'){
                document.forms[formIndex].elements[elementIndex].style.visibility = 'hidden';
            }
        }
    }
}
function showAllSelects()
{
    for (var formIndex=0;formIndex < document.forms.length;formIndex++) {
        for (var elementIndex=0;elementIndex < document.forms[formIndex].elements.length;elementIndex++) {
            if(document.forms[formIndex].elements[elementIndex].type.substr(0,6) == 'select'){
                document.forms[formIndex].elements[elementIndex].style.visibility = 'visible';
            }
        }
    }
}