Overriding listbox selection using input box

[vizz3108]

I have 2 tables as follows.

Master:

 Kerberos , Name, title

101, Jack, A

102, John, B

103, Jill, C

Info:

Title, Salary

A, 1

B, 2

C, 3

Say I have selected John. Then I will see "Title" as B and "Salary" as 2 in listbox.

Requirement: 

I want to have an input box to input Title, but here is the condition.

If input box is empty, display default salary for selected Title, else display salary for the input box text. 

So I want the input box to override list box selections of "Title". 

[jwjackso]

I used the following expression in the ListBox:

=Aggr(If(Len(vTitle) = 0,Salary,only({1<Title={"$(vTitle)"}>}Salary)),Salary)

[vizz3108]

Many Thanks!!