I have made an email service for my college as a project of Web Technology, which has same architecture and use cases like this one.
SOFTWARE SPECIFICATION REQUIREMENTS :
[1] Implement in HTML.
[2] Two actors- Customer and Administrator.
[3] Customer can book ticket, on basis of flight and seat number.
[4] Administrator can send offer on basis of their Birth date and uses.
So, this won't be a hard one. Looking forward to hearing form you.
Thank you.