var DDSPEED = 2;
var DDTIMER = 15;

// main function to handle the mouse events //
function ddMenu(id,d){
  try
  {
    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);
    }
  }
  catch(err)
  {
    var txt="Error description ddMenu: " + err.description + "\n\n";
    txt+="Click OK to continue.\n\n";
    alert(txt);
  }
}

// collapse the menu //
function ddCollapse(c){
  try
  {
    c.timer = setInterval(function(){ddSlide(c,-1)},DDTIMER);
  }
  catch(err)
  {
    var txt="Error description ddCollapse: " + err.description + "\n\n";
    txt+="Click OK to continue.\n\n";
    alert(txt);
  }
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(id){
  try
  {
    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);
    }
  }
  catch(err)
  {
    var txt="Error description cancelHide: " + err.description + "\n\n";
    txt+="Click OK to continue.\n\n";
    alert(txt);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d){
  try{
    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);
    }
  }
  catch(err)
  {
    var txt="Error description ddSlide: " + err.description + "\n\n";
    txt+="Click OK to continue.\n\n";
    alert(txt);
  }
}
function change_bgr(key,style)
{
  try
  {
    document.getElementById("bm_"+key+"_left").className = 'bookmark_'+style+'_left';
    document.getElementById("bm_"+key+"_center").className = 'bookmark_'+style+'_center';
    document.getElementById("bm_"+key+"_right").className = 'bookmark_'+style+'_right';
  }
  catch(err)
  {
    var txt="Error description change_bgr_normal: " + err.description + "\n\n";
    txt+="Click OK to continue.\n\n";
    alert(txt);
  }
}