function addStyles()
{
    var agent = navigator.userAgent.toLowerCase();
    var isIE6, isIE7, isIE8, isFF, isSafari;
	
    isIE6 = (agent.indexOf("msie 6")>=0);
    isIE7 = (agent.indexOf("msie 7")>=0);
    isFF = (agent.indexOf("firefox")>=0);
    isSafari = (agent.indexOf("safari")>=0);


    if(isIE6 && !isIE7)
        document.write ('<link href="/css/ie6.css" type="text/css" rel="stylesheet" />');
    if((isIE7 && isIE6) || isIE7)
        document.write ('<link href="/css/ie7.css" type="text/css" rel="stylesheet" />');
    if(isFF)
        document.write ('<link href="/css/ff.css" type="text/css" rel="stylesheet" />');
    if(isSafari)
        document.write ('<link href="/css/safari.css" type="text/css" rel="stylesheet" />');
}


function showSub(o)
{
    hideAll();
  
    var sub = o.getElementsByTagName('ul')[0];
    if(sub)
        sub.style.display = 'block';
}

function hideSub(o)
{
    o.style.display = 'none';
}

function hideAll()
{
   var NavigationContainer = document.getElementById('NavigationContainer');

    var subs = NavigationContainer.getElementsByTagName('ul');
    for (var i=0; i< subs.length; i++)
        if(subs[i].className == 'sub')
            hideSub(subs[i]);
}