// Slide menu module
// Author: Petros Ioannidis, 2004
// Copyright: (c)2004 Petros Ioannidis interACT eK, Germany
// Copying and use of this code is allowed for personal usage only and when the 
// copyright notice included aswell.
var menuname   = "leftmenu";
var bottomname = "footer";
var ystart = 0;
var top    = 0;
var bottom = 0;
var menu   = 0;
var ns6 = document.getElementById && !document.all ? 1 : 0;
var ie  = document.all ? 1 : 0;

function init_slidemenu()
{
  if ( !ie && !ns6 || !document.getElementById(menuname) )
    return;

  menu = document.getElementById(menuname);

  if ( document.getElementById(bottomname) )
    bottom = document.getElementById(bottomname);

  top = menu.offsetTop;
  slidemenu();
}

function slidemenu()
{
  if ( ns6 )
  {
    if ( window.pageYOffset > top )
      ydiff = ystart - window.pageYOffset + top;
    else
      ydiff = ystart;
  }
  else if ( ie )
  {
    if ( document.body.scrollTop > top )
      ydiff = ystart - document.body.scrollTop + top;
    else
      ydiff = ystart;
  }

  if ( (ydiff < (-50)) || (ydiff > (50)) )
    ystart -= Math.round(ydiff / 30);
  else if ( (ydiff < (0)) || (ydiff > (0)) )
    ystart -= Math.round(ydiff / Math.abs(ydiff));

  if ( (ystart + menu.offsetHeight + top) >= bottom.offsetTop )
    ypos = bottom.offsetTop - menu.offsetHeight - top;
  else
    ypos = ystart;

  menu.style.top = ypos;

  setTimeout("slidemenu()", 10);
}

window.onload = init_slidemenu;