Add a people group attribute in list programatically

Question

I want to add a attribute (Person or Group) in List through coding, does any one know how to do it.

thanks

Answer 1

[Saboor's comment re-posted as an answer, with minor modifications]

SPSite site = SPContext.Current.Site;
using (SPWeb web = site.OpenWeb())
{
  SPListCollection lists = web.Lists;
  SPList list = lists['Guid for List'];
  list.Fields.Add("people", SPFieldType.User, false);
  list.Update();
}

Answer 2

Itm["AssignedTo"] = new SPFieldLookupValue(Vti, "");

here vti is USserID or GroupID