Advanced UDF

Folks,

I was trying to write a UDF which will generate 5 target instace , but I am getting an error that

<i><b>Cannot produce target element /FIDCCP01/IDOC. Check xml instance is valid for source xsd and target-field mapping fulfills requirements of target xsd</b></i>

I have written this function

for ( int i = 0; i < 5; i++ )
  {

       result.addContextChange();
       i++;
  }

Can anybody help sorting out the problem

Manish