VB.Net Mdichild focus problem ?

[nomenklatura]

Hi,
I have a main menu which parent mdi form
and i opening two mdi child form (frm1,frm2) with listview doubleclick
event on main menu..
ex:
Dim frm As New frm1

frm.MdiParent = Me

frm.Show()

Ok, there isn't problem
But when two child forms opened, and try this forms open again , i couldn't
use top code , because this code create new same form ..
So i try to activate (focus) opened child form if it is loaded..
I use boolen variabel and set frm1loaded event isfrm1loaded=true when frm1
first created..
Maybe you have a better idea this problem..
So my code:
If Isfrm1 = True Then

frm1.ActiveForm.Focus()

Else

Dim frm As New frm1

frm.MdiParent = Me

frm.Show()

End If
But frm1.ActiveForm.Focus() couldn't work..???
i want to activet frm1
If this frm1 behind to frm2, it didn't bring front to frm2 ..
How can i ?
If i use visualbasic 6 , solve tihis problem very easy
But .net form management very complex and i colund't find examples in msdn..

Thanks in advance..
Note:I am from Turkey and my primitive language is Turkish.. Execuse for my
english :)