PlayersOnMapHighIndex messed up

[GIAKEN]

Code:

Sub HandleAttack(ByVal Index As Long)
Dim i As Long, n As Long
Dim Damage As Long

    ' Try to attack a player
    For i = 1 To High_Index
        i = PlayersOnline(i)
        Index = PlayersOnline(Index)

It highlights the last line there. I could fix it, but I'm too busy to look further into it.