Scenario:

We provide a hosted site that clients pay to use internally (a tool to support their business workflow). We have a requirement to provide a form that the clients can 'embed' in their outward facing site. This form will permit a member of the public to enter some details to register an interest - this data will be pushed to our remote system.

Question:

I'm currently planning on creating a simple HTML page that the client's web guys can include in a simple fashion on their site (either using an iframe or an object tag). If I do this, am I going to run into difficulties when the user tries to submit the embedded form (as it will be going to different domain to the one they are currently browsing)?

I had a look at google adsense and I see that they just provide a link to a JS file that renders their ads - I'm not sure I see the advantage in this, but if anybody has any bright ideas...

Whatever technique that gets used, I'll have to authenticate the request as coming from my client's site(s).