function showTab(n,obj) {
	 var tabCurrent="content_main_left_pic_"+obj;
	 var tabTitleCurrent="tab_title_"+obj;
     var tabList;
	 var tabTitle;
     for(var i=1;i<=n;++i){
		 tabList="content_main_left_pic_"+i;
		 tabTitle="tab_title_"+i;
		 document.getElementById(tabList).style.display = "none";
		 document.getElementById(tabTitle).className='content_main_left_page1';
		 }
	 document.getElementById(tabCurrent).style.display ="block";	
	 document.getElementById(tabTitleCurrent).className="content_main_left_page2";
}