Without your code, it is difficult to comment accurately on what is wrong with it! Instead, I would use this code to add the textbox to my panel:
TextBox tb = new TextBox();
tb.Width = 100;
tb.Height = 50;
tb.Location = new Point(10,10);
tb.Text = "My New TextBox";
myPanel.Controls.Add(tb);
And I would use this code to access it:
foreach(Control c in myPanel.Controls)
{
TextBox tb = c as TextBox;
if (tb != null)
{
Control.WriteLine(tb.Text);
}
}
What are you doing that is different?