Creating multiple idoc

Hi Experts,

I am doing file to idoc Scenario. the file contains one header with multiple item lines. if i send one header with multiple line item it wll create one idoc with one header with multiple idoc. suppose if i send a file which contains multiple header with multiple item lines then it should create as many idoc as header in the file.

ex:

Header1

+++itemline1

+++itemline2

Header2

+++itemline1

+++itemline2

the above example should create 2 idoc .

plz provide some solution.

Thanks in advance,

Venu