Hi
I believe, you want to create a textbox at run-time. If so, try following code in Page_Init.
TextBox1 = New TextBox();
TextBox1.ID = "txtMyTextBox";
TextBox1.Style("Position") = "Absolute";
TextBox1.Style("Top") = "50px";
TextBox1.Style("Left") = "200px";
Form1.Controls.Add(TextBox1);
Hope that helps.
-Milind