We need about 40 web page forms auto filled out from JSON

We need about 40 forms filled out on a secure website. The website uses cookies for user sessions and uses hidden form fields that will need to be posted along with the form data. Each form has between 3-10 form fields and errors are shown in an error html DIV. A sample of the hidden form fields which will need to be passed <input type="hidden" name="indvId" value="7693476"> <input type="hidden" name="fname" value="asdf asdf"> <input type="hidden" name="editFlag" value="false"> <input type="hidden" name="cancelFlag" value="false"> <input type="hidden" name="[login to view URL]" value="0"> <input type="hidden" name="nxtGenFooternumber" value="6fe542-956d-4ebe-902b-a99fa08662f2"/> A sample of the fields to fill in <input type="text" name="[login to view URL]" maxlength="50" size="30" value="" id="line1"> <input type="text" name="[login to view URL]" maxlength="30" size="30" value="" id="line2"> We will give you a JSON file with something along the lines of "person": { "lastCity": "285679", "lastState": "10286018", } We would like it written in C# or vb.net so it can be built into our current project Some forms will need to be submitted multiple times but will be separated in the JSON for each submit, E.G. the last form would need to be submitted again for person2. This project will have to make the account using the website before logging in / filling out the forms. The website also runs slow and might have timeout issues or kick the session out, so a re-login and error checking mechanism must be built in.