show datatable alert

i have a problem, after i'm click button show this alert:

DataTables 开发者_如何转开发warning: Unable to re-initialise DataTable. Please use the API to make any configuration changes required.

what the meaning of this alert??what must i do?i want after click button data grid can show data...

$("#show").click(function(event){
                        if (typeof oTable=='undefined'){
                                oTable = $("#datalist").dataTable({
                                .
                                .
                                .
                                });
                        }else{
                                oTable.fnDraw();
                                }
                     });