put this stuff in the section where you first declared your variables

Go above where you typed this stuff:
Dim whichKey As IntegerDim whichLetter As StringDim allTheWords As String

And add this array there:

Dim CodeKeys() As String = {"Q", "W", "E", "R", "T", "Y", "U", "I", "O", "P", "A", "S", "D", "F", "G", "H", "J", "K", "L", "Z", "X", "C", "V", "B", "N", "M", " "}