CHECK_float

Description: Checks if the input value is a float number and shuts down the application if not.
Parameter:

• val: Input value to check.
• allowEmpty: Set to true if you want to allow empty strings.
• returnNoDie: Set to true if you want to return (instead of aborting the program) when an error in the input is found.

Returns:

• The input value if it's a float number or false on an error.