How to retrieve a value from a function using return in vb.net?

[vbdotnet]

I want to retrieve a value from a function using return.
Like this:

Sub Main()
dim x as integer = 10
getX(x)
'how do I get z in here?
End Sub

Function getX(value as integer)
dim z as integer = value + 3
return z
End function

[Rabbit]

Dim zValue
zValue = getX(x)