code to block an ip address

'variable declarations
Dim UserIP as String
Dim flag as Integer = 0
Dim arrayIPs(1) as String
'Assign the blocked IP Addresses in an array
arrayIPs(0) = "127.0.0.01"
arrayIPs(1) = "100.45.76.80"
'get the users IP address
UserIP = Request.ServerVariables("LOCAL_ADDR")
'looping through the banned IP addresses
For i = 0 to arrayIPs.Length-1
'display a message and stop processing the page
If UserIP = arrayIPs(i) Then
flag  = flag + 1
End If
Next
If (flag <> 0) then
MessageBox.Show("You are not an authorized user to access this website")
Else
MessageBox.Show("Valid Users")
End If