328.

In my Web Form i.e asp.net form I have a control of DropDownList having 2 values of Mumbai and Delhi.
On submit of a button I redirect my page to same URL.Instead of 2 values in DropDownList,I am able to see 4 values i.e 2 of Mumbai and 2 of Delhi each.

Why?

private void Page_Load()
{
  if (!IsPostBack)
  {
     // Validate initially to force asterisks
     // to appear before the first roundtrip.
     Validate();
  }
}