C# ASP.NET for loop issue -

in code behind have list of names...(tracy, michelle , tiffany)

and have string called names , each name gets added string, displays (tracy michelle tiffany)

how after each name gives comma , before last one, put and..

here of code

    string names = "";      for(int i=0; i< groupofpeople.count; i++)     {          groupofpeople nm = (groupofpeople) nm.groupofpeople[i];          names += nm.firstname;                             }  

do 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 += " , " + nm.firstname;           }