Database relationship

Question

Hello,

I'm making a website "Recruitment agency" as a project and i have an issue. I want to use 3 tables

1. Applicants
2.New Jobs
3.Companies

Now i did all this good and well but i cant seem to relate the tables.

eg. i have a reference number for the job so this this should relate to the company? Now the way i'm thinking is

One company can have many job offers "New Jobs".
New Jobs can have many Applicants.
Applicants can have many new Jobs.
Company can have many Applicants.

This is so confusing i don't know how to do this.

When i use asp to add an "New Job" it gives me an error saying "Can't add because table is related to another account"

Help Please