function isArray(o) {   
  return Object.prototype.toString.call(o) === '[object Array]';    
}  

function showTab(tag,index){   
   var styleName=tag;
   var tab_txt=document.getElementsByName(tag+"_txt");
   var tab_more=document.getElementsByName(tag+"_more");
   var tab=document.getElementsByName(tag);
   for(var i=0;i<tab.length;i++){
      if(i==index){
		tab[i].className=styleName+"_1";
		tab_txt[i].style.display="block";
		if(tab_more && tab_more.length>0){
			tab_more[i].style.display="block";
		}
	  }else{
		tab[i].className=styleName+"_2";
		tab_txt[i].style.display="none"; 
		if(tab_more && tab_more.length>0){
			tab_more[i].style.display="none";
		}
	  }
   }
}