Changing from webform to webform

I have 2 webforms the first one has a dropdown. Once you make the selection and click the enter button, it will open the second form. As I add more forms, there will be more entries in the dropdown. In windows app it was as easy as show and hide but webforms does not seem to have a similar function. What is the proper way to switch from one webform to another without opening a new browser window? Is it using parent and child?

if you are saying that you have a drop down box say for example

credit cards if the card was switch then you would require the issue number simply make the element visable is the users selection is switch

same rule applys but just show and hide panels.

To do it without refreashing the page, use javascript

hope it helps