Merging is when you combine a range of cells to create a new, larger cell. This is a great way to create a label that spans several columns or several rows. You can easily create a cell span in the view port, row header, or column header area by using the addSpan method of Sheet object, and remove the span from a merged cell by using the removeSpan method. 
Go to Wijmo web site to read entire blog and source code.
MESCIUS inc.