Tabellenzeilen-Mausklick-Hervorhebungseffektcode, implementiert durch JS_Javascript-Kenntnisse

<script type="text/javascript">
var highlightcolor='#E0F2FE';
var clickcolor='#ffedd2';
function MouseOver(){
 var source=event.srcElement;  
 if (source.tagName=="TD"){  
  source=source.parentElement;
  var cells = source.children; 
  if (cells[0].style.backgroundColor!=highlightcolor&&cells[0].style.backgroundColor!=clickcolor)
   for(i=0;i<cells.length;i++){
    cells[i].style.backgroundColor=highlightcolor;
   }  
 }
}
function MouseOut(){ 
 var source=event.srcElement;
 if (source.tagName=="TD"){ 
  source=source.parentElement;
  var cells = source.children; 
  if (cells[0].style.backgroundColor!=clickcolor) 
   for(i=0;i<cells.length;i++){
    cells[i].style.backgroundColor="";
   }  
 }
}
function MouseClick(){
 var source=event.srcElement;
 if (source.tagName=="TD"){ 
  source=source.parentElement;
  var cells = source.children;
  if (cells[0].style.backgroundColor!=clickcolor)
   for(i=0;i<cells.length;i++)
    cells[i].style.backgroundColor=clickcolor;   
  else
   for(i=0;i<cells.length;i++)
    cells[i].style.backgroundColor=""; 
 }
}
</script>
<table onmouseover="MouseOver()" onclick="MouseClick()" onmouseout="MouseOut()" cellspacing="0" bordercolordark="#ffffff" bordercolorlight="#cccccc" border="1" width="80%" align="center" style="cursor:pointer"> 
 <tr>
  <td>1</td>
  <td>a</td>
  <td>b</td>  
 </tr>
 <tr>
  <td>2</td>
  <td>c</td>
  <td>d</td>  
 </tr>
 <tr>
  <td>3</td>
  <td>e</td>
  <td>f </td>  
 </tr> 
 <tr>
  <td>4</td>
  <td>g</td>
  <td>h </td>  
 </tr> 
</table>