Newbie - need to round field to 2 decimal places

Hello all:

Newbie trying to creating labels and trying to round field to 2 decimals. the below line yields the following result:

Output = this["QTY_TOPICK"].ToString();

When I print the label I get "60.00000". I need to reduce it to "60.00" and am unsure of how code this. I believe this is c#.

When you have a chance please advise.

Thanks,

Rm103