Form Builder Tool

[sss]

Hello,

We are enhancing our product to let users create their own "custom"
forms . Is their any tool in the market that we can use that would help
us in acheiving this. The tool must (at the very least)

a) allow the user to create a form using Labels, textboxes,
dropdownlists etc.,
b) allow the user to align these controls in the form
c) provide a API so that the form layout can be stored in the database
for later retreival.
If any of you guys know of any tool that acheive the above
functionality, please reply.

Thanks
Satish