Anyway, here is a good way to allow only number to be input into the textbox for the port:
Private Sub TextBox_KeyPress(KeyAscii As Integer)
Select Case KeyAscii
Case 8, 48 To 57 '8 is backspace, 48 to 57 is 0 to 9
KeyAscii = 0
There must also be some checks to make sure the starting port is less than and not equal to the ending port, starting port must be more than 0 and less than 65535 and this also goes to the ending port.
Another thing is that if I put 100 max connections and the port range is less than 100 ports, then the scanner will scan beyond the port range!