function setTab(obj,idstr){
									    var pn=obj.parentNode;
									    var lis = pn.getElementsByTagName("li");

									    for (i = 0; i < lis.length; i++) {
										   lis[i].className=lis[i]==obj?"tab_this":"";
										   document.getElementById(idstr+i).style.display=lis[i]==obj?"":"none";
										   }
									}