chamilo-lms2/app/Resources/public/assets/modernizr/feature-detects/forms-formattribute.js

// Detects whether input form="form_id" is available on the platform
// E.g. IE 10 (and below), don't support this
Modernizr.addTest("formattribute", function() {
	var form = document.createElement("form"),
		input = document.createElement("input"),
		div = document.createElement("div"),
		id = "formtest"+(new Date().getTime()),
		attr,
		bool = false;

		form.id = id;

	//IE6/7 confuses the form idl attribute and the form content attribute
	if(document.createAttribute){
		attr = document.createAttribute("form");
		attr.nodeValue = id;
		input.setAttributeNode(attr);
		div.appendChild(form);
		div.appendChild(input);

		document.documentElement.appendChild(div);

		bool = form.elements.length === 1 && input.form == form;

		div.parentNode.removeChild(div);
	}

	return bool;
});