Fetching CellValue out of Datagrid - need help

HI All,

      I am a newbie to C#. I have currently Read a data of series of numbers from a notepad file as a dataset and displayed it in a datagirdview control. Now I need to do some manipulations within the data in the datagrid. The sample data looks like this.

        For example :          COL1     COL2   COL3
                                      5          5          8        
                                      8           4          6
                                      2           7          4


                  Here I should find the difference between first row (COL1) and second row(COL1). If this difference is lesser than a certain value (ex: 8-5 > 4) then I should remove the second row from the datagrid. For this reason I am trying to fetch Cellvalue from the datagrid and overcomming problems with that. Requesting help for this problem.

Thanks in advance,

Arun