function UseXPCOM(f) {
    return function() {
        netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
        return f.apply(this, arguments);
    };
};

/** Open file for binary writing access */
openFileForBinaryWrite : UseXPCOM(function(filename) {
	this.outputFilename = filename;
        this.outputFile = Components.classes["@mozilla.org/file/local;1"].createInstance(Components.interfaces.nsILocalFile);
        this.outputFile.initWithPath(filename);
        var stream = Components.classes["@mozilla.org/network/file-output-

        // PR_WRONLY + PR_CREATE_FILE + PR_APPEND, default mode, no behaviour flags
        stream.init(this.outputFile, 0x02 | 0x10, 00600, false);
        this.stream = Components.classes["@mozilla.org/binaryoutputstream;1"].createInstance(Components.interfaces.nsIBinaryOutputStream);

        this.stream.setOutputStream(stream);
}),