Script Problem - Schneefall

<script language="JavaScript1.2">






  var snowsrc="snow2.gif"
  var no = 10;


  var ns4up = (document.layers) ? 1 : 0;
  var ie4up = (document.all) ? 1 : 0;


  var dx, xp, yp;
  var am, stx, sty;
  var i, doc_width = 800, doc_height = 600;


  if (ns4up) {
    doc_width = self.innerWidth;
    doc_height = self.innerHeight;
  } else if (ie4up) {
    doc_width = document.body.clientWidth;
    doc_height = document.body.clientHeight;
  }


  dx = new Array();
  xp = new Array();
  yp = new Array();
  am = new Array();
  stx = new Array();
  sty = new Array();


  for (i = 0; i < no; ++ i) {
    dx[i] = 0;
    xp[i] = Math.random()*(doc_width-50);
    yp[i] = Math.random()*doc_height;
    am[i] = Math.random()*20;
    stx[i] = 0.02 + Math.random()/10;
    sty[i] = 0.7 + Math.random();
    if (ns4up) {
      if (i == 0) {
        document.write("<layer name='dot"+ i +"' left='15' top='15' visibility='show'><img src='"+snowsrc+"' border='0'></a></layer>");
      } else {
        document.write("<layer name='dot"+ i +"' left='15' top='15' visibility='show'><img src='"+snowsrc+"' border='0'></layer>");
      }
    } else if (ie4up) {
      if (i == 0) {
        document.write("<div id='dot"+ i +"' style='POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;'><img src='"+snowsrc+"' border='0'></a></div>");
      } else {
        document.write("<div id='dot"+ i +"' style='POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;'><img src='"+snowsrc+"' border='0'></div>");
      }
    }
  }


  function snowNS() {
    for (i = 0; i < no; ++ i) {
      yp[i] += sty[i];
      if (yp[i] > doc_height-50) {
        xp[i] = Math.random()*(doc_width-am[i]-30);
        yp[i] = 0;
        stx[i] = 0.02 + Math.random()/10;
        sty[i] = 0.7 + Math.random();
        doc_width = self.innerWidth;
        doc_height = self.innerHeight;
      }
      dx[i] += stx[i];
      document.layers["dot"+i].top = yp[i];
      document.layers["dot"+i].left = xp[i] + am[i]*Math.sin(dx[i]);
    }
    setTimeout("snowNS()", 10);
  }


  function snowIE() {
    for (i = 0; i < no; ++ i) {
      yp[i] += sty[i];
      if (yp[i] > doc_height-50) {
        xp[i] = Math.random()*(doc_width-am[i]-30);
        yp[i] = 0;
        stx[i] = 0.02 + Math.random()/10;
        sty[i] = 0.7 + Math.random();
        doc_width = document.body.clientWidth;
        doc_height = document.body.clientHeight;
      }
      dx[i] += stx[i];
      document.all["dot"+i].style.pixelTop = yp[i];
      document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]);
    }
    setTimeout("snowIE()", 10);
  }


  if (ns4up) {
    snowNS();
  } else if (ie4up) {
    snowIE();
  }


</script>