how can i create usercontrol with dyamically create textbox

Hi All,

i Want to Create one Windows for Voucher Entry like below

Item Name                                                                  Qty        Rate        VAT         Amount

abc                                                                                1           100        16%         116 (when i enter or tab on last textbox

new textbox line hear                                                                                                       i need to create another text box

                                                                                                                                           line below previous one)

can any one help me about this to create one user control for this windows?

Regard!

Hitesh Patel