I am trying to insert a node (Row) in excel xml file. While trying to create a node and assign it to XMLDocumentFrag ment object it throws an error " 'ss' is an undeclared namespace." to me.

XmlDocumentFrag ment docFrag = this.document.C reateDocumentFr agment();

docFrag.InnerXm l = @" <Row ss:AutoFitHeigh t=""0"" ss:Height=""127 .5"">
<Cell ss:StyleID=""s3 1""><Data...