function rollOver(theImage, graphicName)

    {

        theImage.src = '/images/nav_'+graphicName+"_on.gif";

    }

    function rollOut(theImage, graphicName)

    {

        theImage.src = '/images/nav_'+graphicName+"_off.gif";

    }

    var currentSection;

    var _timeoutInterval;

    

    function showSubMenu(sectionName){

        if (_timeoutInterval) {

            clearTimeout(_timeoutInterval);

            delete _timeoutInterval;

        }

        if (currentSection && currentSection != sectionName) {

            document.getElementById("sub_menu_"+currentSection).style.visibility = 'hidden';

        }

        currentSection = sectionName;

        document.getElementById("sub_menu_"+currentSection).style.visibility = 'visible';

    }

    function clearSubMenu(sectionName){

        _timeoutInterval = setTimeout("_clearSubMenu()", 300);

    }

    function _clearSubMenu(){

        if (currentSection) {

            document.getElementById("sub_menu_"+currentSection).style.visibility = 'hidden';

        }

        delete currentSection;

        delete _timeoutInterval;

    }