[BeaucoupFish]

You were told to declare max as a constant, but you didn't use it to initialise the array:

Const max As Integer = 30
Dim a(max) As Integer

Scope: you have declared the string s globally and again locally. You should lose all the global declarations, make them all local.

Also, note that in VB at least, the following declaration makes i a variant, and j an integer
Dim i, j As Integer

Either do

Dim i As Integer, j As Integer

or better yet

Dim i As Integer
Dim j As Integer

Actually, you are not even using the second variable.
Finally, from your supplied code, I cannot imagine you are getting much output.

Why not populate your string as you loop through setting the array values? Also, please note spacing and indentation for awesome readability [img]/images/graemlins/smile.gif[/img] (only shows up using .... sorry)

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
....Const max As Integer = 30
....Dim a(max) As Integer
....Dim i As Integer
....Dim s As String

....s = "initial data:" & vbNewLine

....For i = 0 To 9
........a(i) = i * -11
........s = s & a(i) & " "
....Next

....s = s & vbNewLine

....For i = 10 To 19
........a(i) = -i
........s = s & a(i) & " "
....Next

....s = s & vbNewLine

....For i = 20 To 29
........a(i) = i
........s = s & a(i) & " "
....Next

....s = s & vbNewLine

....Call MsgBox(s)

End Sub