1. You can open advanced editor on the right upper side (link in blue font color) of the input area.
2. The xml in your the last post... Is that the original input?
3. That last xml is not well formed. See http://www.w3schools.com/xml/xml_validator.asp Especially the line "<<xs1:Sellerno>1</<xs1:sellerno>"... seems wrong. Also there are numerous namespace conflicts. Please provide a well formed example.
Cheers