// Add Listener
function addListener(elem,eventType,func,cap) {
  if(elem.addEventListener) {
    elem.addEventListener(eventType,func,cap);
  } else if(elem.attachEvent) {
    elem.attachEvent('on' + eventType,func);
  } else {
    return false;
  }
}

// Expand & Collaps Nav 
function expand_nav(id) 
  {
    var expand_box = eval(document.getElementById(id+'_box'));
    var expand_img = eval(document.getElementById(id+'_pic'));
  
    if(expand_box.style.display == 'block') 
      {
        expand_box.style.display = 'none';
        expand_img.src = "images/arrow_off.gif";
  
      } 
    else 
      {
        expand_box.style.display = 'block';
        expand_img.src = "images/arrow_on.gif";
      }
  }


// Expand & Collaps Nav 
function showDropNav(id)
  {
    hide_all();
    if(document.getElementById(id))
      {
        document.getElementById(id).style.display = "block";
      }
  }

function hide(id)
  {
    if(document.getElementById(id).style.diplay == "block")
      {
        document.getElementById(id).style.display = "none";
      }
  }

function hide_all()
  {
    var container =  document.getElementById('nav_container');
    var divs = container.getElementsByTagName('div');
    
    for(i=0;i<divs.length;i++)
      {
      divs[i].style.display = "none";
      }
  }

function rollover(img, on)
{

  off = img.src;
  id = img.id;
  subnav = id+"_subnav";
  offfull = img.src;
  onfull = on;
  if(off.lastIndexOf('/') != -1) // if there is a path, strip it
    {
       off = off.substring(off.lastIndexOf('/')+1);
    }
  if(on.lastIndexOf('/') != -1) // if there is a path, strip it
    {
       on = on.substring(on.lastIndexOf('/')+1);
    }
  if(on != off)
    {  
      off_ex = off.substring(off.lastIndexOf('.')) // extract extension
      off = off.substring(0,off.lastIndexOf('.')); //strip extension
      on_ex = on.substring(on.lastIndexOf('.')) // extract extension
      on = on.substring(0,on.lastIndexOf('.')); //strip extension
      eval(off + " = new Image(); ");
      eval(off + ".src = '" + offfull +"'");
      eval(on + " = new Image(); ");
      eval(on + ".src = '" + onfull +"'");
      var image_on = eval(on + ".src");
      var image_off = eval(off + ".src");
      img.onmouseover = function() { img.src = image_on;}
      img.onmouseout = function() { img.src = image_off;}
      
    } 
}