Convert negative value to positive value in a row of Gridvie

Question

Hi,

 

Am calling some datas from database and binding it in gridview. I need one of my row not to display its negative values. I have tried many ways but dint see any proper result to overcome.

 

 

I have tried something like this,

 

string formattedValue = string.Format("{0:$#.##;$-#.##}", sales);

 

sales is the row which are giving both negative and positive values. I need to display all the values in positive values only. Dont want to update the database table to positive.