var agent = navigator.userAgent.toLowerCase();
var ie = (agent.indexOf("msie") != -1);

function value(layer_id,data_var){
  return eval("parseInt(document.getElementById('" + layer_id + "').style." + data_var + ")");
}

function moveLayer(layer_id,x,y){
  eval("document.getElementById('" + layer_id + "').style.left = value('" + layer_id + "','left')+x;");
  eval("document.getElementById('" + layer_id + "').style.top = value('" + layer_id + "','top')+y;");
}

function positionLayer(layer_id,x,y){
  eval("document.getElementById('" + layer_id + "').style.left = x;");
  eval("document.getElementById('" + layer_id + "').style.top = y;");
}

function sizeLayer(layer_id,w,h){
  eval("document.getElementById('" + layer_id + "').style.width = w;");
  eval("document.getElementById('" + layer_id + "').style.height = h;");
}