Jquery在textarea的文字焦点中插入文字

var txtArea = $("#textArea")[0];
            var content = txtArea.value;
            var start = txtArea.selectionStart; //初始位置
            txtArea.value = content.substring(0, txtArea.selectionStart) + $(this).text() + content.substring(txtArea.selectionEnd, content.length);
            var position = start + $(this).text().length;
            $("#textArea").focus();
            txtArea.setSelectionRange(position, position);