How to create a textbox dynamically

 Hi All,
 Can any one let me know "How to create a textbox dynamically".
 This is my requirement exactly.
I have a web form with a 2Textboxes and a button. When I enter a numeric number and click on the button.  We should be able to generate the textboxes. For example if I enter "9" in the textbox and clicked on button. 9 Textboxes should be created dynamically. I will be entering Numeric data into the textboxes, once i enter the data  the last textbox should be update with the sum of 9 Textboxes. Can any one let me know "How do I ahcieve this".
Thanks and Regards,
 Sandeep

 
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