[Solved] C# ASP.NET for loop issue [closed]

Do something like

for(int i=0; i< GroupOfPeople.Count; i++)
        {
            GroupOfPeople nm = (GroupOfPeople) nm.GroupOfPeople[i];
                if(i < GroupOfPeople.Count - 1)
                    names += nm.FirstName + ", ";
                else
                     names += " and " + nm.FirstName;

         }