var divs = ['td1', 'td2']; 
function DivShowHide(targetElement,contentElement, change) 
  {
      var tarElement = document.getElementById(targetElement);
      var srcElement = document.getElementById(contentElement);
      
      if(tarElement != null && srcElement  != null) 
	  {
       tarElement.innerHTML=srcElement.innerHTML;	   
      }	
	  for(i=0; i<divs.length; i++)
		{ 
        document.getElementById(divs[i]).className='shownobg';		
        } 
		document.getElementById(change).className='showbg';
   		//document.getElementById(img).className='shownobg';	
  }