When user is trying to login in ESS/MSS/ASS portal are you receiving error "You are not authorized to access Portal. Please contact Admin....!" ?
Possible are the scenarios when you will see this error message
1) You must have entered wrong Employee code
2) Your HR might not be enabled you portal access for you
If you are HR, please follow the article How to manage employees portal access? to enable portal for your employees.
If you are an employee, please contact your HR to enable portal access for you.