just realized that part.thanks very much @sela007!

i modified the swap() function to be like below and it seems to be working now.

Private Sub swap(ByRef a As Integer, ByRef b As Integer)
        ' swaps the values, and swaps for all corresponding columns after that to keep each column together
        Dim temp, temp2 As Integer
        temp = a
        temp2 = b

        b = temp
        a = temp2

    End Sub

i dont know how to thank you.millions of thanks to you!

now i have to retrieve the Team names from my database to replace the numbers as team.
hope it will be easy.

thanks again.

yes. ByVal or ByRef, it underlines under

(s(r1, 0)

the error says
'Value of type integer cannot be converted to two-dimensional array'

hey thanks. i really hope that if i can solve the swap() function, this program will run.

@m_wylie85 is that what function swap() in C++ really does? thanks.

is there any predefined function in vb.net for the same function?

@sela007 thanks for your effort.i'm quite bad in algorithm.

well, i have succeed in running the unscheduled matches. its just the scheduled part that give me headache. the swap function is really killing me.

plus, EXIT WHILE below is translated from BREAK; in C++.
am i translating it correctly?
i think the loop is infinite loop when i use EXIT WHILE.

If count = 2 Then
084
con = False
085
Exit While
086
 
087
End If
088
b = b + 1
089
End While

i'm sorry.my bad.

actually i'm translating all the codes from C++ program.
i tried to google what swap() function do in C++, but i can't find the definition.
i think it is to swap the value inside the two-dimensional array.
the swap() function below is wrong.it return an integer, not an array.

Protected Sub btnGenerate_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnGenerate.Click
Dim team As Integer
Dim redo As Char
Dim cost As Double
Dim match As Integer = 0
Dim r1, r2 As Integer
Dim count As Integer = 0
Dim a, b As Integer
Dim result, result2, result3, result4, result5, result6 As String
Dim counterString As String
Dim con As Boolean = False
Dim Gen As System.Random
Gen = New System.Random(My.Computer.Clock.TickCount)

team = CInt(txtTeam.Text)

a = 1
While a < team
match = match + a
a = a + 1

End While

'to run the unschedule matches

Dim s(match - 1, 2) As Integer
Dim counter As Integer = 1

a = 1
While a < team
b = a + 1
While b <= team
s(counter - 1, 0) = a
s(counter - 1, 1) = b

result = System.Convert.ToString(s(counter - 1, 0))
result2 = System.Convert.ToString(s(counter - 1, 1))
counterString = System.Convert.ToString(counter)
result3 = "Match " + counterString + " : Team " + result + " VS Team " + result2

lstResult.Items.Add(result3)
counter = counter + 1

b = b + 1

End While
a = a + 1

End While


'to run scheduled matches
con = False
While con = False
a = 0
While a < 5
' swapping pairs randomly before start scheduling
r1 = Gen.Next(1, match + 1).ToString
r2 = Gen.Next(1, match + 1).ToString

swap(s(r1, 0), s(r2, 0))
swap(s(r1, 1), s(r2, 1))

a = a + 1
End While

con = True
count = 0
a = 1
While a <= team

b = 0
While b < match

If s(b, 0) = a Or s(b, 1) = a Then
count = count + 1

Else
count = 0

End If

If count = 2 Then
con = False
Exit While

End If
b = b + 1
End While

a = a + 1
End While

End While

'Displaying result

a = 1
While a <= match
result4 = System.Convert.ToString(s(a - 1, 0))
result5 = System.Convert.ToString(s(a - 1, 1))
counterString = System.Convert.ToString(a)

result6 = "Match " + counterString + " : Team " + result4 + " VS Team " + result5
lstResult.Items.Add(result6)
a = a + 1
End While

End Sub

Private Sub swap(ByVal swapArr(,) As Integer, ByVal row As Integer)
' swaps the values, and swaps for all corresponding columns after that to keep each column together
Dim temp As Integer
For column = 0 To swapArr.GetUpperBound(1) - 1
temp = swapArr(column, row)
swapArr(column, row) = swapArr(column, row + 1)
swapArr(column, row + 1) = temp
Next
End Sub