how to get basic block ID of a statement inside visit* methods

Hi,

How can we get basic block id (blockID) of a statement when we override visit* methods?

e.g. for a basic block given below, when VisitIfStmt() is visited, how to get blockID inside this visit method?
  [B4]
    1: x == 0
    T: if [B4.1]
    Preds (1): B6
    Succs (2): B3 B2

- Rajendra