[RESOLVED] sum grid column

I have this code to loop on all the rows of the column and sum them up. But like if I have 20 and 20.50 the sum should be 40.50 but on the textbox of the result, I am getting
either round down or round up of the result like 41. How can I code it to present the decimals.

The format of the column that I use to format the number is #,###.00


Resolved:

change or remove the data type of my variable that holds the sum up value.