YES !! I have solved the problem .

I have seen that the name of the original DataTable is ("NewUser") and not (0) as I referred it on the second page.

The other mistake was that I created another row on the second page, and I didn’ t need to add a new one, simply continue adding on the same row, so there was to write
‘row = ds.Tables(0).Rows(0)’ instead of ‘row = ds.Tables(0).NewRow()’.


Now I create all the table on the first page, and on the second I only continue filling the row created on the first page with the new data for the rest of the columns.


Now all runs fine. But now I have a little doubt in my mind, Why I need to define the data type of the DataTable columns? Thus:
Code:
dt.columns.add("Mail", System.Type.GetType("System.String"))
I think that I don’ t need to define it because the form controls (fields) are well defined all with their data type (textbox, ddl (DataValueField),..), and I have validators as well. And once reaches to the DataTable all the values are correct. Maybe the problem would appear in some inserts into the database, but now the insert that I do with 17 fields of this DataTable works fine.

What do you know about the necessity of defining the data type on the DataTable columns?

Thank you VM,
Cesar