Mapping Problem-Mapping not sufficient Error Message

Hello SDNers,

I m facing one problem, details are as below

Source Structure

MT_Source

Invoice 1..unbound

Type 1..1

Invoice Header 1..1

PartyID

ID 1..1

DocuID

ID 1..1

InvoiceLine 1..unbound

Item 1.1

InvoiceSubline 1.unbound

costCentre 1..1

GL Code 1..1

Target Structure

MT_Target

Target 1.unbound

Bgr00

Stype 1..1

Xkeep 1..1

Bkpf 1..1

Stype 1..1

Tcode 1..1

Bldat 1..1

bukrs 1..1

Bseg 1..1

Stype 1..1

Tbnam 1..1

newbs 1..1

wrbtr 1..1

zunor 1..1

Bseg1 1..unbound

Stype 1..1

Tbnam 1..1

newbs 1..1

wrbtr 1..1

zunor 1..1

Mapping need to be done in such a way like

Invoice Header must go in the corresponding fields of BKPF ,BSEG

Invoice Line fields must go in the corresponding fields of BSEG1

I tried split by Value with a user defined function copyPerValue

public void copyPerValue(String[] a,String[] b,ResultList result,Container container){

for(int i=0;i<=a.length;i++)

{

result.addValue(b[0]);

}

}

InvoiceLine----

CopyPerValue ->SplitBYValue[EachValue] ->bldat

DocumentDateTime----

but I m getting Mapping not sufficient Error Message.

Pls help me in getting resolve this problem.

Thx in advance