My I94 expiring on 9/20 & new I94 is Eff 10/1.How tomaintain lawful status?

From Employer A - I’m in L1 visa and it is expiring on 10-Sept-2012. Also my I-94 is expiring on 20-sept 2012.

Employer B has filed my H1B and I also got an approval with new I-94 from effective 01-Oct-2012. Now my question is how to maintain lawful status for 10 days starting from 21-sept to 30-Sept without leaving USA and reentering with new H1B stamped in my passport. Or without going into H4 or F visa and then do COS etc.

Please advise.

Much Thanks in advance.