JavaScript Decryption

Hello all, This is a quick project, if successful, there will be multiple projects that will follow.. Here's the description. Visit this link: [login to view URL] It opens up Google "I am not a robot" CAPTCHA.. When you click the checkbox, it opens up 9 image to choose the correct images. At this point a request is sent to "[login to view URL]" that has querystring "bg" in it. I want to programatically generate this "bg" without opening the page. Also, when you select correct images and click "Verify" another request is sent to "[login to view URL]" with "bg" in it form data. I also want to programatically generate this "bg" without opening the page. I want the code in C# to generate these 2 "bg". I already have the code to verify the image. Its ok if you give only the code to generate "bg" but that "bg" should be working to verify the images.