Merge merging or Split spliting GridView Header Row or columns in Asp.Net 2.0 / 3.5

In most of the times for reporting purpose we need to merge or merging GridView header columns or rows or to use multiple headers in Asp.Net C# Vb.Net code. In this article or Asp.Net C# tutorial i will explain how one can merge or split GridView Header rows or columns. For this example here i took product table. Where In first two columns i will show Brand Name & Category Name & by spliting i