MID$ (string, offset)
MID$ (string, offset, length)

   Synopsis:
      Returns a string within a string

   Examples:
      To return everything in the string from the 10th character onwards:
      
         MID$ ("To be or not to be", 10)     >> "not to be"
         
      To return 5 characters in a string, starting from the 10th character:
      
         MID$ ("To be or not to be", 10, 5)  >> "not t"
