Jim,
See my answer to your previous post re: getting a manual. Once you have the manual, take a look at pg. 43 "Logo Messages". This explains how to program the receipt message. If you've initialized the register, you may need to set the logo message format (pg. 51) first. Also, take a look at "Text Programming" on pg. 39 for how to actually enter text. If you need more help, post again and I'll try to help.
Steve, July 2010