var isNetscape4 = document.layers;
var isNetscape6 = document.getElementById && !document.all
var isNetscape = isNetscape4 || isNetscape6;
var isIE = document.all && !isNetscape;
var DHTML = document.getElementById || document.all || document.layers;



function getStyle(nom) {
  if (isNetscape6)
    style = document.getElementById(nom).style;
  else if (isNetscape4)
    eval("style = document."+nom);
  else
    style = document.all[nom].style;
  return(style);
}


function clipping(nom, x1, y1, x2, y2) {
  if (isNetscape4) {
    getStyle(nom).clip.left = x1;
    getStyle(nom).clip.top = y1;
    getStyle(nom).clip.right = x2; 
    getStyle(nom).clip.bottom =  y2;
  }
  else if (isNetscape6)
    getStyle(nom).clip = "rect("+y1+" "+x1+" "+y2+" "+x2+")";
  else
    getStyle(nom).clip = "rect("+y1+" "+x2+" "+y2+" "+x1+")";
}

function deplacement_absolu(nom, abscisse, ordonnee) {
  if (!DHTML)
    return;
  getStyle(nom).left = abscisse;
  getStyle(nom).top = ordonnee;
}

function deplacement_relatif(nom, deltaX, deltaY) {
  if (!DHTML)
    return;
  getStyle(nom).left = parseInt(getStyle(nom).left) + deltaX;
  getStyle(nom).top = parseInt(getStyle(nom).top) + deltaY;
}