Components.interfaces.nsIFilePicker.modeGetFolder return document. getAnonymousElementByAttribute(this, "anonid", "text").value; document. getAnonymousElementByAttribute(this, "anonid", "text").value = val; this.setAttribute("value", val); var ev = document.createEvent("HTMLEvents"); ev.initEvent("change", true, false); this.dispatchEvent(ev); var f = Components.classes["@mozilla.org/file/local;1"]. createInstance(Components.interfaces.nsILocalFile); f.initWithPath(this.value); return f; this.value = val.path; var fp = Components.classes["@mozilla.org/filepicker;1"]. createInstance(Components.interfaces.nsIFilePicker); fp.init(window, "Choose Directory", this._type); fp.appendFilters(Components.interfaces.nsIFilePicker.filterAll); try { fp.displayDirectory = this.file; } catch (e) { } if (fp.show()) return; this.value = fp.file.path; Components.interfaces.nsIFilePicker.modeOpen