var emailfilter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
var phonefilter = /^(\d{3})\D*(\d{3})\D*(\d{4})\D*(\d*)$/;

function returnObject (id) {
	if (document.all) {
		return document.all[id];
	} else if (document.getElementById) {
		return document.getElementById(id)
	} else if (document.layers) {
		return document.layers[id];
	}
	return null;
}

function isDigit(num) {
	if (num.length = 0) { 
		return false;
	}
	var string = "1234567890";
	if (string.indexOf(num) != -1) {
		return true;
	}
	return false;
}

function isInteger(string) {
	if (string.length = 0) {
		return false;
	}
	for (var i = 0; i < string.length; i++) {
		if (!isDigit(string.charAt(i))) {
			return false;
		}
	}
	return true;
}

function verifyCredentials () {
	var username = document.getElementById('username');
	var password = document.getElementById('password');
	
	if (username.value.length > 32) {
		alert('Username must be 32 characters or less');
		username.focus();
		return false;
	}
	if (username.value == '') {
		alert('You must enter a username');
		username.focus();
		return false;
	}
	if (password.value.length > 32) {
		alert('Password must be 32 characters or less');
		password.focus();
		return false;
	}
	if (password.value == '') {
		alert('You must enter a password');
		password.focus();
		return false;
	}
	return true;
}

function verifyContact () {
	var name = document.getElementById('name');
	var email = document.getElementById('email');
	var comments = document.getElementById('comments');
	
	if (name.value == '') {
		alert('Please enter your name');
		name.focus();
		return false;
	}
	if (!emailfilter.test(email.value)) {
		alert('Please enter a valid email address');
		email.focus();
		return false;
	}
	if (comments.value == '') {
		alert('Please enter your comments');
		comments.focus();
		return false;
	}
	return true;
}

function searchterm_populate () {
	if (returnObject('searchterm')) {
		if (returnObject('searchterm').value == '') {
			returnObject('searchterm').value = 'Search Site';
		}
	}
	return true;
}

function searchterm_validate () {
	var searchterm = returnObject('searchterm');
	
	searchterm_onclick();
	
	if (searchterm.value == '') {
		alert('Please enter a keyword or keywords to search for.');
		searchterm.focus();
		return false;
	}
	return true;
}

function searchterm_onclick () {
	var searchterm = returnObject('searchterm');
	
	if (searchterm.value == 'Search Site') {
		searchterm.value = '';
		searchterm.focus();
	}
	return true;
}
			
function searchterm_onblur () {
	var searchterm = returnObject('searchterm');

	if (searchterm.value == '') {
		searchterm.value = 'Search Site';
	}
	return true;
}