javascript et w3c

j'aimerais faire passer ce script aux normes W3C mais il ne pass epas:
<script language="javascript">

<!-- DEBUT DU SCRIPT -->
/*
Snow Effect Script
Created and submitted by Altan d.o.o. (snow@altan.hr,  http://www.altan.hr/snow/index.html)

EDITE SUR L'EDITEUR JAVASCRIPT
http://www.editeurjavascript.com
*/

  var snowsrc="images/goutte.png"
  var snowsrc2="images/goutte2.png"
  var no = 3;/*ici on change le nombre de goutte a afficher en meme temps sur l'ecran*/
  var ns4up = (document.layers) ? 1 : 0;
  var ie4up = (document.all) ? 1 : 0;
  var nn6up = (document.getElementById) ? 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;
}

else if (nn6up)
{
doc_width = self.innerWidth;
doc_height = self.innerHeight;
}

  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='"+snowsrc2+"' border=0></layer>");
}

else
{
document.write("<layer name=dot"+ i +" left=15 top=15 visibility=show><img src='"+snowsrc+"' border=0></layer>");
}
}

else if (ie4up || nn6up)
{
  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></div>");
  }
  
  else
  {
document.write("<div id=dot"+ i +" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc2+"' 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);
  }

function snowNN6()
{
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.getElementById("dot"+i).style.top = yp[i];
  document.getElementById("dot"+i).style.left = xp[i] + am[i]*Math.sin(dx[i]);
}

setTimeout("snowNN6()", 3);/*vitess des gouttes*/

  }
  if (ns4up) {
snowNS();
  } else if (ie4up) {
snowIE();
  } else if (nn6up) {
snowNN6();
  }

</script>

<!-- FIN DU SCRIPT -->

et voici les debuts d'erreurs:
Line 309, Column 30: required attribute "type" not specified
<script language="javascript">

&#9993;

The attribute given above is required for an element that you've used, but you have omitted it. For instance, in most HTML and XHTML document types the "type" attribute is required on the "script" element and the "alt" attribute is required for the "img" element.

Typical values for type are type="text/css" for <style> and type="text/javascript" for <script>.
Line 355, Column 23: character ";" not allowed in attribute specification list
  for (i = 0; i<no; ++ i)

&#9993;
Line 355, Column 23: element "no" undefined. Did you mean "noframes" or "noscript"?
  for (i = 0; i<no; ++ i)

&#9993;

You have used the element named above in your document, but the document type you are using does not define an element of that name. This error is often caused by:
incorrect use of the "Strict" document type with a document that uses frames (e.g. you must use the "Frameset" document type to get the "<frameset>" element),
by using vendor proprietary extensions such as "<spacer>" or "<marquee>" (this is usually fixed by using CSS to achieve the desired effect instead).
by using upper-case tags in XHTML (in XHTML attributes and elements must be all lower-case).
Line 368, Column 36: Attribute "name" exists, but can not be used for this element.
document.write("<layer name=dot"+ i +" left=15 top=15 visibility=show><im

&#9993;

You have used the attribute named above in your document, but the document type you are using does not support that attribute for this element. This error is often caused by incorrect use of the "Strict" document type with a document that uses frames (e.g. you must use the "Transitional" document type to get the "target" attribute), or by using vendor proprietary extensions such as "marginheight" (this is usually fixed by using CSS to achieve the desired effect instead).

This error may also result if the element itself is not supported in the document type you are using, as an undefined element will have no supported attributes; in this case, see the element-undefined error message for further information.

How to fix: check the spelling and case of the element and attribute, (Remember XHTML is all lower-case) and/or check that they are both allowed in the chosen document type, and/or use CSS instead of this attribute. If you received this error when using the <embed> element to incorporate flash media in a Web page, see the FAQ item on valid flash.



merci de m'aider

Bonjour,

Plusieurs choses :
- rajoute type="text/javascript" à ta balise <script>
- Je ne pense pas que la balise <layer> soie reconnu par W3C
- Tes attributs left et top doivent comporter une unité or tu à ça par exemple :

document.getElementById("dot"+i).style.top = yp[i];

à remplacé par : document.getElementById("dot"+i).style.top = yp[i]+'px';

Je ne sais pas pour les attributs pixelTop et pixelLeft, mais ça doit surement être pareil