Problem to modify fields in datawindow

Hello everyone, I am doing something simple, I create a DataWindow with only 3 fields, placed in a window, the window have a single line edit to input a code and then do a retrieve.

Public posting on iis, all good, run the application, put a code and recovering well, but then wanting to change one of the data can not access the field,

Where will be the problem?

They put the tab order, have a gap in my head

Thanks for any help

regards