structure problem

I used this in vb6 with no problem but now I have one.

structure SizedStructure
public ThisItem as Single
end structure

Dim ELSA() as SizedStructure
Dim SelectedSt as SizedStructure

--I then went
redim preserve ELSA(1)
--Assigned info into structure

SelectedSt = ELSA(0)

I then assigned data to
SelectedEl.ThisItem = 5

The problem it also modifies ELSA(0).ThisItem

I want ELSA(0) to stay intact