QA_Expression Evaluation using Stacks_Simulation_p1

[kolliSuman]

Defect Description:
In the Simulation page of " Expression Evaluation using Stacks experiment , if we enter the invalid values in corresponding field and if we click on the "=" button still the simulation process is working instead an error message should be displayed on the screen as to enter the valid values

Actual Result :
In the Simulation page of " Expression Evaluation using Stacks experiment , if we enter the invalid values in corresponding field and if we click on the "=" button still the simulation process is working

Environment:
OS: Windows 7, Ubuntu-16.04,Centos-6
Browsers: Firefox-42.0,Chrome-47.0,chromium-45.0
Bandwidth : 100Mbps
Hardware Configuration:8GBRAM ,
Processor:i5

Test Step Link:
https://github.com/Virtual-Labs/data-structures-iiith/blob/master/test-cases/integration_test-cases/Expression%20Eval/Expression%20Eval_08_Simulation_p1.org

Attachment:

[khushpreet-kaur]

Refer to #32 (comment)