Sort a listbox

[stratos]

Hello guys!
I have a problem to sort the results in a listbox.
Here is an example of what I mean

dim l as integer 
dim m as integer 
dim x as integer 'input value for loop
dim y as integer 'input value for loop
dim z as double

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

For Me.L = 1 To x ' user gives the x
For Me.M = 1 To y ' user gives the y
z = l*M
ListBox1.Items.Add("(" & L & "," & M & ")= " & z)
Next M
Next L

Exit Sub

I am trying to find a way to sort the results in columns in this way:
When the first 'L' loop ends then go to next column of the listbox.
Let's say the user gives x=5 and y=8. I would like to have a listbox
like this one in the attachment.
I have tried the listbox proporties ''Horizontal Scrollbar''
and ''MultiColumn'' but it didn't help... The sorting depends
on ListBox Height-Width. Any ideas?