Automatically sign up for a TUMonline course. There is another version, but this seams to be the good one. I don't remember.

autoSignup.js

function startSignup(){
	//extract necessary data from dom
	if(document.getElementById("autoSignupFrame") != null){
		alert("The script is already running. Please reload and try again to change something.");
		return;
	}

	var firstGroup = document.getElementsByClassName("list")[0].getElementsByClassName("z1")[0].getElementsByTagName("td")[0].getElementsByTagName("a")[0].innerHTML;

	var gruppe = window.prompt("Gruppe", firstGroup);

	function sameName(elem){
		return elem.innerHTML.toLowerCase().trim() == gruppe.toLowerCase().trim();
	}
	var gTag = Array.prototype.slice.call(document.getElementsByTagName("a")).filter(sameName)[0];

	if (gTag == undefined){
		alert("This doesn't look like a vaild name");
		return;
	}

	var tr = gTag.parentNode.parentNode;

	//later needed to fill out the form
	function isGrpNr(elem){
		return elem.name == "cststudnr";
	}
	var pLVGrpNr = Array.prototype.slice.call(tr.getElementsByTagName("input")).filter(isGrpNr)[0].value.split("/")[0];


	function isStartingTime(elem){
		return (elem.getAttribute("headers") == "hdrANM hdrANMVON");
	}
	var startingString = Array.prototype.slice.call(tr.getElementsByClassName("C")).filter(isStartingTime)[0].innerHTML;

	var splitString = startingString.split(',');
	var timeFragments = splitString[1].split(':').map(function(a){return parseInt(a);});
	var dateFragments = splitString[0].split('.').map(function(a){return parseInt(a);});

	var startingTime = new Date(2000 + dateFragments[2], dateFragments[1] - 1, dateFragments[0], timeFragments[0], timeFragments[1]);


	//draw time ui
	if(startingTime < new Date()){
		alert("Sorry, but this script can't make you travel back in time. Yet...");
		return;
	}

	var div = document.createElement('div');
	document.body.appendChild(div);
	div.id = "autoSignupFrame";
	div.style.width = "240px";
	div.style.height = "78px";
	div.style.padding = "30px";
	div.style.border = "2px solid #a1a1a1";
	div.style.borderRadius = "20px";
	div.style.backgroundColor = "white";
	div.style.fontSize = "20px";
	div.style.color = "black";
	div.style.top = "0";
	div.style.bottom = "0";
	div.style.left = "0";
	div.style.right = "0";
	div.style.margin = "auto";
	div.style.position = "absolute";
	div.style.textAlign = "center"
	div.style.fontFamily = ["Helvetica Neue", "Helvetica", "Arial"];

	div.innerText = "Milliseconds to start time:";


	var timeleft = document.createElement('div');
	div.appendChild(timeleft);
	timeleft.style.marginTop = "10px"
	timeleft.style.fontSize = "40px";
	timeleft.style.color = "#a1a1a1";

	timeleft.innerText = "4000";

	timeLoop();

	//actual form sending
	function done(){
		with (document.forms[0]){
			//??
			pLVGrpProfNr.value = "";
			pPHOrgNr.value = "";
			pPHOrgName.value = "";
			pPHOrgKennung.value = "";	

			cgrpnr.value=pLVGrpNr;
			csave.value="J";
			submit();
		};
	}

	function timeLoop(){
		var now = new Date();
		if (now > startingTime) return done();
		timeleft.innerText = (startingTime - now).toString();
		now = new Date();
		window.setTimeout(timeLoop, 1000 - now.getMilliseconds());
	}
}