overriding fnClick in tabletool for PDF

Hi,
I am extending datatable pdf and have provided an implementation for pdf fnclick function. If I remove this function the "Save as" shows up. However, when I provide an implementation of fnClick, it shows both the the alerts but not the "Save As Dialog".

"fnClick": function (nButton, oConfig, flash) {
alert('Hi Before');

                    this.fnSetText(flash, "title:" + this.fnGetTitle(oConfig) + "\n" + "message:" + oConfig.sPdfMessage + "\n" + "colWidth:" + this.fnCalcColRatios(oConfig) + "\n" + "orientation:" + oConfig.sPdfOrientation + "\n" + "size:" + oConfig.sPdfSize + "\n" + "--/TableToolsOpts--\n" + this.fnGetTableData(oConfig));

                    alert('Hi After');
                }