var search = {
	// configuration
	config : {
		formId : 'search', // id used for <form> element
		sectionId : 'section', // id used for <select> element
		sectionLabel : 'Section', // label text used for <select> element
		allSectionsText : 'All sections' // <option>all sections</option>
	},
	
	// preps the form elements for action
	init : function() {
		// does the form exist? if not, quit now
		if (!document.getElementById(search.config.formId)) return;
		var searchForm = document.getElementById(search.config.formId);
		// loop through all the form elements
		for (i=0; i<searchForm.elements.length; i++) {
			var el = searchForm.elements[i];
			// if the elements are <selects>, continue
			if (el.nodeName == 'SELECT') {
				search.ifSection(el);
				search.addEvent(el, 'change', function() { search.ifSection(this); });
			}
		}
	},

	// checks the values of the sites and if applicable, creates a section input
	ifSection : function(el) {
		switch (el.value) {
			case 'http://www.neme.org/main/?q=':
				search.createSection(section=[null, 'archives', 'texts', 'arts_info', 'calls']);
			break;

			case 'http://neme-imca.org/?q=':
				search.createSection(section=[null, 'events', 'exhibitions', 'projectinform', 'publications']);
			break;

			default:
				search.removeSection();
		};
	},

	// create's a section select and options
	createSection : function(section) {
		// if any section selects exist, remove them
		search.removeSection();
		// create label element
		var label = document.createElement('label');
			label.setAttribute('for', search.config.sectionId);
			// create and attach label text
			label.appendChild(document.createTextNode(search.config.sectionLabel));
		// create select element
		var select = document.createElement('select');
			select.setAttribute('id', search.config.sectionId);
			select.setAttribute('name', 'section');
			// insert <select> into <label>
			label.appendChild(select);
		// build <option>s
		for (i=0; i<section.length; i++) {
			// create <option>
			var option = document.createElement('option');
				option.setAttribute('value', section[i]);
			// create <option>text</option>
			var optionText = document.createTextNode((section[i] === null) ? search.config.allSectionsText : section[i]);
				option.appendChild(optionText);
			// insert <option> into <select>
			select.appendChild(option);
		};
		// insert <select> after first label
		search.insertAfter(label, document.getElementById(search.config.formId).getElementsByTagName('label')[0]);
	},
	
	// helper function that makes up for the DOM's lack of insertAfter
	insertAfter : function(newElement, targetElement) {
		var parent = targetElement.parentNode;
		if (parent.lastChild == targetElement) {
			parent.appendChild(newElement);
		} else {
			parent.insertBefore(newElement, targetElement.nextSibling);
		}
	},

	// removes any sections
	removeSection : function() {
		if (document.getElementById(search.config.sectionId)) {
			var toRemove = document.getElementById(search.config.sectionId);
			/*
				The following is a little complex, but it saves a for loop. Key:
				JS:    toRemove---->.parentNode---->.parentNode
				HTML:  <select>----><label>--------><fieldset>
			*/
			toRemove.parentNode.parentNode.removeChild(toRemove.parentNode);
		}
	},
	
	// cross-browser way to add events to objects
	addEvent: function(obj, event, fn) {
		// for the smart kids
		if (obj.attachEvent) {
			obj["e"+event+fn] = fn;
			obj[event+fn] = function() { obj["e"+event+fn]( window.event ); }
			obj.attachEvent( "on"+event, obj[event+fn] );
		} else {
			obj.addEventListener(event, fn, false);
		}
	}
};

// load search magic!
search.addEvent(window, 'load', search.init);