Placeholder is dumping all my data after like one call

I followed a quick guide on using a placeholder to put in a table.   This is eing called out of a method called GenerateBoard() and it is called when a button is clicked.1 PlaceHolder1.Controls.Clear(); 2 Table tb1 = new Table(); 3 PlaceHolder1.Controls.Add(tb1); 4 TextWriter stdout = new StreamWriter("C:/test.txt"); 5 6 for (int i = 0; i < data.GetLength(0); i++) 7 { 8 TableRow tr = new TableRow(); 9 for (int j = 0; j < data.GetLength(1); j++){ 10 TableCell tc = new Tabl ...