PDF Format using iTextSharp

Hi,

 

 

            In my application i using the iTextSharp(3.0.3.0).dll to export the data into PDF files. I want to format the table's colum with rowspan. But i couldn't set the rowspan for the cell.   for example: I used the following format.

Col1	col2	col3	col4
Row1Col1	Row1Col2	Row1Col3	bottom1
Row2Col1	Row2Col2	Row2Col3	bottom1
Row3Col1	Row3Col2	Row3Col3	bottom1

 

 Now i want merge the all "bottom1" cell into a single cell. How could do this.  

 

 

Thanks in Advance.