Problem in Receiving the files that had been attached with my web form using a html file input

Hello there!,

I am having trouble in receiving the attached files from a html file input !.

First of all i have added a master page and made this form as a content page!

Actaully the view state of this html file input is not maintaining when the page is posted back!. It says Request.Files.Count=0 even i had attached a file!

Before adding the master page it worked fine!

Could you please tell me a solution!,
My Code is

if (Request.Files.Count != 0)
{
HttpFileCollection files = Request.Files;
DataTable Table4 = new DataTable();


DataColumn Doc_Name = new DataColumn();
Doc_Name.ColumnName = "Documents";

DataColumn Remove = new DataColumn();
Remove.ColumnName = "Remove";

Table4.Columns.Add(Doc_Name);

Table4.Columns.Add(Remove);
for (int ...