changing primary key value

hi

i want to experiment that can we change the primary key value

I am making a table Employee with Id as primary key and name as other columns

and another table salery with emp_id as foreign key and salary as another column

on windows form

on button 1 click data should be inserted on both the tables is it possible

or i have to save the employee table first and then salary table

is it possible to give temperory id in salary as -1 -2 -3 and after inserting data in employee table it should take that id and replace with this one