function replaceButtons(buttons, backName, backUrl)
{
  var menu = document.getElementById('button_menu');
  
  // remove all children from element
  while (menu.firstChild) {
    menu.removeChild(menu.firstChild);
  }

  //Let's create some new buttons
  for (i=0; i<buttons.length; i++)
  {
    var button = buttons[i].createButton();
    menu.appendChild(button);
  }
}

function Button(name,link,type,target) {
  this.name=name;
  this.link=link;
  this.link_target=target;
  this.type=type;
  
  this.createButton = function ()
  {
    var button = document.createElement('div');
    var link = document.createElement('a');
    button.id = (this.type=='subButton'?'subButton':'button');
    link.href=this.link;
    link.innerHTML = name;
    if (this.link_target != '') link.target = this.link_target;
    button.appendChild(link);
    return button;
  }
}