I'm taking a guess here cuz you didn't give us much:
If you have a User Input that requires a number, and if what they entered was not a number, then you want to force them to re-enter the input, then you want to use a label to send them back up to the top before the IF.
Example:
LABEL TryAgain
Display.InputDialog Title: $'''Enter a number''' Message: $'''No really, it has to be a number''' InputType: Display.InputType.SingleLine IsTopMost: True UserInput=> UserInput ButtonPressed=> ButtonPressed3
BLOCK 'Not a number'
ON BLOCK ERROR
GOTO TryAgain
END
Text.ToNumber Text: UserInput Number=> UserInputNumber
END
