Script funktioniert nicht - Suchfeldeingabe automatisch löschen

(function() {
    var searchbar = document.getElementById("searchbar");
    
    searchbar.doSearch = function(aData, aWhere, aEngine, aParams, aOneOff) {
    let textBox = this._textbox;


      if (aData && !PrivateBrowsingUtils.isWindowPrivate(window) && this.FormHistory.enabled) {
        this.FormHistory.update({
            op: "bump",
            fieldname: textBox.getAttribute("autocompletesearchparam"),
            value: aData,
        }, {
            handleError(aError) {
              Cu.reportError("Saving search to form history failed: " + aError.message);
            },
        });
      }


      let engine = aEngine || this.currentEngine;
      let submission = engine.getSubmission(aData, null, "searchbar");
      let telemetrySearchDetails = this.telemetrySearchDetails;
      this.telemetrySearchDetails = null;
      if (telemetrySearchDetails && telemetrySearchDetails.index == -1) {
        telemetrySearchDetails = null;
      }


      const details = {
        isOneOff: aOneOff,
        isSuggestion: (!aOneOff && telemetrySearchDetails),
        selection: telemetrySearchDetails,
      };
     // BrowserSearch.recordSearchInTelemetry(engine, "searchbar", details);


      let params = {
        postData: submission.postData,
      };
      if (aParams) {
        for (let key in aParams) {
          params[key] = aParams[key];
        }
      }
      openTrustedLinkIn(submission.uri.spec, "tab", params);


      this.value = '';
          
      this.currentEngine = this.engines ? this.engines[0] : this._engines[0];
    };

}());