Default values into Dataset

[EAI]

Hi All,

I am creating a dataset from a schema. Now I want to populate the dataset
using an xml which confirms to that schema. But the problem is that not all
the elements have data. So I get an error "Input string was not in a correct
format" because the number of columns does not match. How do I make dataset
take default value(null) when there is no data for some elements(Columns)?
Please help.

Thanks!