How to create TextBoxes on Button Click using ASP.Net,C#

Question

In my website a user can send Greeting Cards to one or more than one person. For this, he will enter the Receiver name in one textbox and Receiver EmailId in another textboxand then click on "Send" button. If he wants to send more than one person then he will click on "Add More" button. when he cliks on "Add More" then two text boxes are created dynamically. one text box is for entering Receiver Name and another text box is for entering "Receiver Email Id". Each time when he clicks on "Add More" button then two text boxes are created. Please suggest me, how i will create two TextBoxes on each button click and get email id from these TextBoxes to send mail ob tthes mail id.