How should it be done?

What's the difference between a computer and the web?

Lots. The Web violates or relaxes many assumptions that conventional programming languages and practices make.

When programming a computers:
When programming the Web:

• Share memory between different parts of a program.
• Share Databases between different pages.
• All functions se the same opcodes, O/S, and usually language.
• Different parts of a 'program' can be on different machines, O/S, languages.
• Processes are well-defined.
• You never know whether a process is ended, or if the user has merely gone out for coffee.
• There is one program counter.
• The user can fork off new copies of the program at will. Arbitrary points in execution can be placed on a hotlist and saved for later use.
• The sequence of execution is controllable by programmer.
• Sequence of execution controlled by user.