Post form responses to Redirect URL

I have a simple form (first name, last name, dollar amount) that I need to post to a separate website for payment processing. 

The payment processsor needs something similar to www.website.com/page.aspx?firstName=xxx&lastName=xxx&amount=xxx

How can I take the three values and post them to the URL i've entered into "Redirect to a page..."?  

Hello Mark,

I want to  make a quick note about your request, as I see that there is an .aspx extension of the page that is going to be requested. Sitefinity 4.4 does not support extensions in the urls of the pages. The only way you can get around that is to use some rewrite module.

However if you want to take have specific values passed to the payment processor you may need to implement a custom logic that uses Request.QueryString. Please consult the following articles:

www.w3schools.com/.../asp_inputforms.asp

http://msdn.microsoft.com/en-us/library/system.web.httprequest.querystring.aspx

and also:

forums.asp.net/.../1

Greetings,
Victor Velev
the Telerik team