public class MyClass
{
public static void ResetTextBoxes(Control oControl)
    {
        foreach (Control c in oControl.Controls)
        {
            if (c is TextBox)
            {
                TextBox t = (TextBox)c.FindControl(c.ID);
                t.Text = string.Empty;
            }
            if (c.HasControls())
            {
                ResetTextBoxes(c);
            }
        }
    }//ResetTextBoxes
}