How to use "rddmmse"

1. Start Stata, and execute "sysdir"
2. Open the directory indicated by "PLUS"
3. If a folder named "r" does not exist at the location "PLUS", create it
4. Move the files "rddmmse.ado" and "rddmmse.sthlp" to the directory
5. Execute "help rddmmse" on Stata to check syntax
