adding textboxes "as requred" to a userform

Hi, hope someone can help, I have a userform with textbox where I can enter say.. "clients name" then that will be inserted into the doc.. what I would like to do is have a command button that will add another identical textbox underneath the first, so I can enter two clients and so on... with a new textbox opening each time I hit the command button.... really got me stumped.. Ive searched everywhere
cheers