extjs 如何给column 加上提示

<script type="text/javascript"src="${pageContext.request.contextPath }/extjs/examples/simple-widgets/qtips.js"></script>renderer : function（value, metaData, record, rowIndex,colIndex, store） {// provide the logic depending on business rules// name of your own choosing to manipulate the cell// depending upon// the data in the underlying Record object.// metaData.css : String : A CSS class name to add// to the TD element of the cell.// metaData.attr : String : An html attribute// definition string to apply to// the data container element within the table// cell （e.g. "style="color:red;""）.metaData.attr = "ext:qtip="" + value + """;return value;}