Remove the textbox and dropdownlist from aspx page and set the thse lines
cmd.Parameters.Add("@SheetName", SqlDbType.VarChar).Value = "sheet1$";
cmd.Parameters.Add("@FilePath", SqlDbType.VarChar).Value = FolderPath + FileName;
cmd.Parameters.Add("@HDR", SqlDbType.VarChar).Value = rbHDR.SelectedItem.Text;
cmd.Parameters.Add("@TableName", SqlDbType.VarChar).Value = "hike";
in place of
cmd.Parameters.Add("@SheetName", SqlDbType.VarChar).Value = ddlSheets.SelectedItem.Text;
cmd.Parameters.Add("@FilePath", SqlDbType.VarChar).Value = FolderPath + FileName;
cmd.Parameters.Add("@HDR", SqlDbType.VarChar).Value = rbHDR.SelectedItem.Text;
cmd.Parameters.Add("@TableName", SqlDbType.VarChar).Value = txtTable.Text;