[MHC] Limitations and Erors

[lkshkmia]

As a user I want to see when the incorrect information is entered so that I will get the correct calculations

Description
Limitations on what the user can enter
Eror messages

Acceptance Criteria

1. User doesn't have the ability to enter letters and other signs, only numbers
2. If the user entered 0 (no other numbers) or negative number, the error "Enter a number greater than 0" should be displayed
3. If the user hasn't entered anything, an eror should appear

This user story is attached to
#910

Tasks

1. • If the user entered 0 or negative number, the error "Enter a number greater than 0" should be displayed