var skip_advance=false;
var curr = false;


function scrollMenu(event, elm)
{
    skip_advance=true;
    if(!event) var event = window.event;



    var offset = elm.offsetParent;


    var my =  event.clientY - elm.offsetTop;
    
    
    my = my + dw_Viewport.getScrollY();
    // alert(my);

    var menu = document.getElementById("menu_contents");
    var menu_height = menu.offsetHeight;
    var pad_height = elm.offsetHeight;
    var delta_height = menu_height - pad_height;
    var delta = delta_height / pad_height;
    
    var ny = (my * delta);


    //  if (ny>(delta-10))ny=(my*delta)+10;
    if (ny<0)ny=0;

    menu.style.top =  - ny + "px";
}

function advanceItem()
{
  if (!skip_advance) {
    var menu = document.getElementById("menu_contents");
    if (!curr) {
	var nodes = menu.childNodes;

	curr = menu.childNodes[0];
    }
    else {
	updateStyle(curr,false);
	
	curr = curr.nextSibling;
	if (!curr)curr=menu.childNodes[0];
    }


    //make selected item fit into the visible area
    var vis = menu.offsetTop + curr.offsetTop ;
    if (vis<0) {
      menu.style.top = curr.offsetTop + "px";
    }
    var offset = menu.offsetParent;
    var pad_height = offset.offsetHeight;
    var delta_height = menu.offsetHeight-pad_height;

    var menu_top = 0;
    if ( (curr.offsetTop + curr.offsetHeight) > pad_height ) {
	menu_top = - curr.offsetTop;

    }
    if (Math.abs(menu_top)+delta_height>pad_height) {
	menu_top = -delta_height;

    }
    menu.style.top = menu_top + "px";
    ////

    updateItem(curr);
  }

  setTimeout("advanceItem()", 5000);
}
function updateStyle(elm, is_sel)
{
  if (elm.className!="sc_menu_item_special") {
    if (is_sel==false) {
      elm.className = "sc_menu_item";
    }
    else {
      elm.className = "sc_menu_item_selected";
      
    }
  }
  
}
function updateItem(elm)
{
  updateStyle(curr,false);
  
  curr = elm;
  
  updateStyle(curr, true);


  var d = document.getElementById("sc_image0_holder");
  var idstr = elm.getAttribute("id");
  var id = idstr.split("_");
// alert(id[1]);
  if (id.length==2) {
    d.src = "/pics/site_update/projects/"+id[1]+".jpg";
  }
  var l = document.getElementById("project_link");
  l.href=elm.href;

  return false;
  
}
var curr_opacity = 1.0;
function fadeOut()
{

  
  var d = document.getElementById("sc_image1_holder");
  updateOpacity(d,curr_opacity);
  curr_opacity = curr_opacity - 0.05;

  if (curr_opacity>0) {
    setTimeout("fadeOut()", 30);
  }
  else {
    var d0  = document.getElementById("sc_image0_holder");
    d.src= d0.src;
    curr_opacity = 1.0;
    updateOpacity(d,curr_opacity);

  }
}
function updateOpacity(elm, val)
{
  
  
  elm.style.opacity = "" + val;
  try {
    elm.style.filter="alpha(opacity="+(val*100)+");";
  }
  catch (e) {

  }
}