Invalid input causes the simulation to freeze, giving no way for the user to go back and correct their input. Not only does the simulation not check for invalid inputs and warn the user, but it doesn't even give the user a way to go back, leaving page reload as the only option.
Steps to reproduce:
Go to this page, and type :: in both the text boxes. Click 'Add' or 'Multiply'.
Expected Result:
The simulation should stop after warning the user of invalid input, and should go back to the input page.
Screenshot:
Actual:
Note the absence of Home button at the right, which usually appears after the simulation is over.
For comparison:
Description
Invalid input causes the simulation to freeze, giving no way for the user to go back and correct their input. Not only does the simulation not check for invalid inputs and warn the user, but it doesn't even give the user a way to go back, leaving page reload as the only option.
Steps to reproduce:
Go to this page, and type
::in both the text boxes. Click 'Add' or 'Multiply'.Expected Result:
The simulation should stop after warning the user of invalid input, and should go back to the input page.
Screenshot:
Actual:
Note the absence of 
Homebutton at the right, which usually appears after the simulation is over. For comparison: