//浮动元素参数
var stop = false;
var ts = 40;
var ctrl = null;
var cid = "FlowingObject";
var mx = 2, my = 2, ml = false, mt = false;
var ow, oh, ol, or, ot, ob;

window.onload = function () {
  ctrl = document.getElementById(cid);
  if (!ctrl) return;
  ow = parseInt(ctrl.style.width, 10);
  oh = parseInt(ctrl.style.height, 10);
  ol = parseInt(ctrl.style.left, 10);
  ot = parseInt(ctrl.style.top, 10);
  //var width = parseInt(window.screen.availWidth) - 22;
  //var height = parseInt(window.screen.availHeight) - 20;
  var width = document.body.clientWidth;
  //var height = document.documentElement.clientHeight||document.body.clientHeight; 
  //var height = document.body.clientHeight; 
  var height = document.documentElement.clientHeight;
  or = width - ow - ol;
  ob = height - oh - ot;
  //window.alert("ow="+ow+",oh="+oh+",ol="+ol+",or="+or+",ot="+ot+",ob="+ob+",w="+width+",h="+height);
  ShowFlowingObject();
  }
  
// 显示浮动元素
function ShowFlowingObject() {
  if (stop) return;
  if (ml) {
    if (ol >= mx) {
      ol -= mx;
      or += mx;
      ctrl.style.left = ol.toString() + "px";
      }
    else ml = false;    
    }
  else { 
    if (or >= mx) {
      ol += mx;
      or -= mx;
      ctrl.style.left = ol.toString() + "px";
      }
    else ml = true;
   }

  var sh=document.body.scrollTop; 
  if (mt) {
    if (ot >= my) {
      ot -= my;
      ob += my;
      ctrl.style.top = (ot+sh).toString() + "px";
      }
    else mt = false;
    }
   else {
    if (ob >= my) {
     ot += my;
     ob -= my;
     ctrl.style.top = (ot+sh).toString() + "px";
     }
    else mt=true;
    }  
  setTimeout(ShowFlowingObject, ts);
  }