My experiments indicate that Mintoris Basic is case sensitive. So the variable "i" is not the same as "I". I only have a soft keyboard so what follows may not apply to machines with a real keyboard. On my machine the letter "i" on it's own (not enclosed in inverted commas or in brackets) is always "corrected" to an "I". This means that if you write your program on your phone be very careful about using "i" as a counter in "for next" loops because you may find that the initial "i" has been capitalized, while the "i" inside the loop has not. This means that they are in fact different variables.