function move_obj(wobj, x, y) {
  document.getElementById(wobj).style.left = x + document.body.scrollLeft;
  document.getElementById(wobj).style.top = y + document.body.scrollTop;
} 

function width_obj(wobj) {
  return document.getElementById(wobj).offsetWidth;
} 

function mover_obj(wobj, x, y) {
  document.getElementById(wobj).style.left = document.body.clientWidth  + document.body.scrollLeft - document.getElementById(wobj).offsetWidth - x;
  document.getElementById(wobj).style.top = y + document.body.scrollTop;
} 

function ancre_obj(wobj, wancre, x, y) { 
  wpx= document.getElementById(wancre).offsetLeft - document.body.scrollLeft + x;
  wpy= document.getElementById(wancre).offsetTop - document.body.scrollTop + y;
  if (wpx<10) wpx=10;
  if (wpy<10) wpy=10;
  move_obj(wobj, wpx, wpy);
}

function centre_obj(wobj, x, y) { 
  wpx= (document.body.clientWidth - document.getElementById(wobj).offsetWidth)/2 + x;
  wpy= (document.body.clientHeight - document.getElementById(wobj).offsetHeight)/2 + y;
  if (wpx<10) wpx=10;
  if (wpy<10) wpy=10;
  move_obj(wobj, wpx, wpy);
}

function centrex_obj(wobj, x, y) { 
  wpx= (document.body.clientWidth - document.getElementById(wobj).offsetWidth)/2 + x;
  wpy= y;
  if (wpx<10) wpx=10;
  if (wpy<10) wpy=10;
  move_obj(wobj, wpx, wpy);
}