Thanks Taximania for finding a version issue and giving it a go. I looked at your website and it was marvelous.
Your right it's a very limited in it's current version and looking at the code again I spotted that I should have tested the TextBox had numeric input.
The program can be a start to a technically harder program by measuring attempts times time to give a score to acheive/beat and then there is moving the goal number by a predictable amount and providing a clue.
I'm bored and have moved on but sometime I'll come back later and tweak it.