Understanding attributes of a http post request

So I'm tr开发者_如何学JAVAying to use a HttpClient to execute a HTTP request against a target site that requires user authentication. Using 'Live HTTP headers', I can see that the post needs to be like this:

https://www.mymeteor.ie/go/mymeteor-login-manager username=0868617*&userpass=**&x=23&y=16&returnTo=%2F

obviously username and userpass are pretty self explanatory. I'm just wondering if anyone can explain what x and y are and if they are important to my post (i.e. can I just leave them out?).

They differ each time I log on and honestly I dont have a clue as to their purpose.

Thanks

---

I believe that x and y are just the coordinates of the point clicked by the user when the submit button is an image. Whether they can be omitted, it depends on what the server does with them. You can just try...