how to clear all textboxes,drop down list at a time in a click event using for each ?

using for each control you can clear all textboxes at a time
why we are choosing for each here is in a wb page there is 80 text boxes then what we have to do

 instead of textbox1.text=""; 

using for each it make an easy
code in .aspx.cs page

protected void btn_new_click(object sender, EventArgs e)
        {

            clear(Page.Controls);
        }

        private void clear(ControlCollection ctrl)
        {
            foreach (Control ctrl1 in ctrl)
            {
                if (ctrl1 is TextBox)
                    ((TextBox)ctrl1).Text = string.Empty;
                else if (ctrl1 is DropDownList)
                    ((DropDownList)ctrl1).ClearSelection();
                clear(ctrl1.Controls);
            }

by using this we can achieve
and using this concept we can reduce the programmer burden