if (document.images) {
  image1on = new Image();
  image1on.src = "homeon.jpg";
  image2on = new Image();
  image2on.src = "videoson.jpg";
  image3on = new Image();
  image3on.src = "songson.jpg";
  image4on = new Image();
  image4on.src = "picson.jpg";
  image5on = new Image();
  image5on.src = "gigson.jpg";
  image6on = new Image();
  image6on.src = "contacton.jpg";

  image1off = new Image();
  image1off.src = "homebutt.jpg";
  image2off = new Image();
  image2off.src = "videobutt.jpg";
  image3off = new Image();
  image3off.src = "songsbutt.jpg";
  image4off = new Image();
  image4off.src = "picturesbutt.jpg";
  image5off = new Image();
  image5off.src = "giglistbutt.jpg";
  image6off = new Image();
  image6off.src = "contactbutt.jpg";
}
function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}

var DDSPEED = 10;
var DDTIMER = 15;

// main function to handle the mouse events //
function ddMenu(id,d){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  clearInterval(c.timer);
  if(d == 1){
    clearTimeout(h.timer);
    if(c.maxh && c.maxh <= c.offsetHeight){return}
    else if(!c.maxh){
      c.style.display = 'block';
      c.style.height = 'auto';
      c.maxh = c.offsetHeight;
      c.style.height = '0px';
    }
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }else{
    h.timer = setTimeout(function(){ddCollapse(c)},50);
  }
}

// collapse the menu //
function ddCollapse(c){
  c.timer = setInterval(function(){ddSlide(c,-1)},DDTIMER);
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(id){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  clearTimeout(h.timer);
  clearInterval(c.timer);
  if(c.offsetHeight < c.maxh){
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d){
  var currh = c.offsetHeight;
  var dist;
  if(d == 1){
    dist = (Math.round((c.maxh - currh) / DDSPEED));
  }else{
    dist = (Math.round(currh / DDSPEED));
  }
  if(dist <= 1 && d == 1){
    dist = 1;
  }
  c.style.height = currh + (dist * d) + 'px';
  c.style.opacity = currh / c.maxh;
  c.style.filter = 'alpha(opacity=' + (currh * 100 / c.maxh) + ')';
  if((currh < 2 && d != 1) || (currh > (c.maxh - 2) && d == 1)){
    clearInterval(c.timer);
  }
}