after annotating can't able to delete the annotated text in ios using webview

"var annotation;\n" +
                    "var json =" + annotation + ";\n" +
                    "annotation = $('#htmlreadingcontent').annotator();\n" +
                    "    annotation.annotator('addPlugin', 'Touch', {\n" +
                    "      force: location.search.indexOf('force') > -1,\n" +
                    "      useHighlighter: location.search.indexOf('highlighter') > -1\n" +
                    "