My implementation of autosuggest

suggestions.js

var SuggestionController = {
  _init: function() {
		SuggestionController.queryInput = document.getElementById("query");
		SuggestionController.suggestionsOutput = document.getElementById("suggestions");
		SuggestionController.queryInput.addEventListener("keyup", SuggestionController.handleKeyup);
	},

	generateSuggestions: function(list, input) {
		if (input === "")
			return [];

		var suggestions = [];
		for (var i = 0; i < list.length; i++) {
			if (list[i].toLowerCase().indexOf(input.toLowerCase()) == 0) {
				suggestions.push(list[i]);
			}
		}

		return suggestions;
	},

	populateSuggestions: function(suggestions) {
		for (var i = 0; i < suggestions.length; i++) {
			var suggestionNode = document.createElement("li");
			var suggestionNodeText = document.createTextNode(suggestions[i]);
		 	suggestionNode.appendChild(suggestionNodeText);
		 	SuggestionController.suggestionsOutput.appendChild(suggestionNode);
		}
	},

	handleKeyup: function(evt) {
		if (SuggestionController._isValidKeyCode(evt.keyCode)) {
			SuggestionController.removeSuggestions();
			var states = ["Arizona", "Official Hacker News T-Shirt", "Thai character", "O'Reilly Media", "Automatic: Your Smart Driving Assistant", "California", "New York", "North Carolina", "New Jersey", "Delaware", "North Dakota"]
			var suggestions = SuggestionController.generateSuggestions(states, SuggestionController.queryInput.value);
			SuggestionController.populateSuggestions(suggestions);
		}
	},

	removeSuggestions: function() {
		var numSuggestions = SuggestionController.suggestionsOutput.childNodes.length;
		for (var i = 0; i < numSuggestions; i++) {
			SuggestionController.suggestionsOutput.removeChild(SuggestionController.suggestionsOutput.childNodes[0]);
		}
	},

	_isValidKeyCode: function(keyCode) {
		if (keyCode < 8 || (keyCode > 8 && keyCode < 32) || (keyCode >= 33 && keyCode <= 46) || (keyCode >= 112 && keyCode <= 123)) {
			return false;
		}
		return true;
	}
};

window.onload = SuggestionController._init;