Submit form using Greasemonkey

Question

The first time, each day, I try to access a web page at work, I get redirected to an internally hosted web page with the IT guidelines and a form with two buttons "Agree" and "Disagree". Clicking "Agree" then allows external internet access for that day and sends you to the site you were originally looking for.

I want to make a Greasemonkey script that auto-submits the form, since I already have a batch file starting up all my normal apps on boot and this would allow me to just leave the PC while it's doing its 20 minute daily start-up ;)

The page only has the one form:

<form method="post">
<input type="submit" value="I Agree" class="agree" onsubmit="submitonce(this)" /> 
<input type="button" onclick="javascript:window.close();" value="I Disagree"
  class="disagree"/>
</form>

And not sure if it matters, since I only need the click, but the function submitonce is:

function submitonce(theform) {
  //if IE 4+ or NS 6+
  console.log("Submitting");
  if (document.all || document.getElementById) {
    //screen thru every element in the form, and hunt down "submit" and "reset"
    for (i = 0; i < theform.length; i++) {
      var tempobj = theform.elements[i];
      if (tempobj.type.toLowerCase() == "submit" ||
        tempobj.type.toLowerCase() == "reset")
        //disable em
        tempobj.disabled = true;
    }
  }
}

I have the rest of the source, but it doesn't look like there is anything else relevant. I haven't really coded before in Greasemonkey/JS, so any help would be appreciated. I'm playing around with an existing userscript that uses CtrlEnter to click the button.

Obviously I don't care if it's a virtual "click" or just a trigger of the submit function, since I'd say they are the same thing aren't they?

Answer 1

It should be a simple job:

// ==UserScript==
// @name           myscript
// @namespace      whatever
// @include        http://path to the internal page
// ==/UserScript==

document.forms[0].submit();

Answer 2

Got some help from a friend who said this should work, though it's not nearly as simple as the answer from dda. Apparently this works in Chrome:

function ClicktheButton(obj) {
  var evt = document.createEvent("MouseEvents");
  evt.initMouseEvent("click", true, true, window,
    0, 0, 0, 0, 0, false, false, false, false, 0, null);
  var cancelled = !obj.dispatchEvent(evt);      
/*

  if(cancelled) {
    // A handler called preventDefault
    alert("cancelled");
  } else {
    // None of the handlers called preventDefault
    alert("not cancelled");
  }
  */
}

var StupidButton = document.querySelector('input[type="submit"][value="I Agree!"]');
ClicktheButton(StupidButton);

And it would also need the includes etc. that GreaseMonkey scripts always have.