function showDiv(num,len,obj,cn)
			{
			 var cssname=cn;
			 for(var id = 1;id<=len;id++)
			 {
			  var ss=obj+id;
			  var snav =obj+"nav"+id;
			  if(id==num){
			  try{document.getElementById(ss).style.display="block"}catch(e){};
			  try{document.getElementById(snav).className=cssname}catch(e){};
			  }else{
			  try{document.getElementById(ss).style.display="none"}catch(e){};
			  try{document.getElementById(snav).className=""}catch(e){};
			  }
			 }  
			}