Write to a third filed based on selection form dropdown.

Write to a third filed based on selection form dropdown.

Hi,

How would I accomplish the following task using an ON-Input Script? 

I have a table where I keep employee Name and info.  In the same form I have filed called Roles which have a value of Admin, Employee 1 ext.  I would like to add an on imput script that would automatically write a value to a third filed called Rate. 

If Input.Empoyee is equal to Admin write $40 to the Rate filed. 

 

Thank you very much for assistance in advance.