function viewdetail(){
	if (document.getElementById("detailbutton").value=="+显示详细元数据") {
		document.getElementById("detailbutton").value="-关闭详细元数据显示";
		document.getElementById("viewdetail").style.display="block";
	} else {
		document.getElementById("detailbutton").value="+显示详细元数据";
		document.getElementById("viewdetail").style.display="none";
	}
}