VS 2008 Decoder - Type A Message In The "message" Text Box And It Spits Out A Code In The "code" Text Box

I'm making a simple decoder. Type a message in the "message" text box and it spits out a code in the "code" text box. If you pop a code into the "code" text box it spits out the message in the "message" text box. Seems simple, right? Well here's my problem. I typed "The quick brown fox jumped over the lazy dog" to test it and it will put a lowercase "f" at the beginning, put letters that aren't supposed to be in there in there, and replace what should be upper case letters with lower case. I commented out the code for replacing symbols because it seemed to work fine before I put them in the code but still the same result. I checked over the code to see if I mixed stuff up. Like I accidentally put the replacement for a lower case "e" as the replacement for a lower case "h" but I can't find anything.

CODE: