How to dynamically add input Box in selection screen on click of Button

Hello

      i want to add new input box at runtime whenever i click on add  button screen  below you  can see see the two screen shot  of my requirement

in the first screen you can see there is only one input field as soon as user click on  add button  it will add one more input field on screen as you can see on second screen .

please help me regarding the issue.

with regards

Sonali