Display currency format upto two decimal place in ASP.Net Label using C#

I have this currency written in code but i want to format it like below

decimal total = Convert.ToDecimal(dt.Compute("SUM(Total)", String.Empty));
Label8.Text = "Total is <b> : " + total.ToString() + "</b>";

format below

decimal total = Convert.ToDecimal(dt.Compute("Sum","N{0:N2}(Total)", String.Empty));
Label8.Text = "Total is <b> : " + total.ToString() + "</b>";

but i get error on Compute