get the value of checkboxlist

hi
im trying to get the values of the checkbox list in the below code 
Dim facilities As String = "" For i As Integer = 0 To facilitiesbuy.Items.Count - 1 If facilitiesbuy.Items(i).Selected Then facilities = facilities & "," & (i) Else End If Next when i try that its get 159876,56489,654654  instrad of 1,2,3,4