how can i show my name in stringfly effect in led cube?

Did you read the Instructables for this?

The project explains how to do what you are asking (and I believe the code is included, but I haven't checked). You may also want to read the comment on THIS PAGE as someone noted an error in the code, and perhaps thats the problem you are having?

At any rate, its usually best to ask questions to the project author (since they know more about the project). You can post a question in the comments, or send the author a PM (private message) by visiting their profile page and clicking on the "Private Message" button. (However it seems the author has been inundated with questions from people who are "in over their heads" on this project, so you may not get a timely reply).