function trip_contact() {
	var none = document.getElementById('contact_none');
	var mail = document.getElementById('contact_mail');
	var phone = document.getElementById('contact_phone');
	var email = document.getElementById('contact_email');
	if (none.checked) {
		mail.disabled = true;
		phone.disabled = true;
		email.disabled = true;
	} else {
		mail.disabled = false;
		phone.disabled = false;
		email.disabled = false;
	}
}
function validate() {
	if ((document.getElementById('opt_investment').checked == false) &&
		(document.getElementById('opt_develop_res').checked == false) &&
		(document.getElementById('opt_develop_com').checked == false) &&
		(document.getElementById('opt_buy_property').checked == false) &&
		(document.getElementById('opt_lease_space').checked == false) &&
		(document.getElementById('opt_buy_home').checked == false) &&
		(document.getElementById('opt_buy_condo').checked == false) &&
		(document.getElementById('opt_learn_more').checked == false) &&
		(document.getElementById('opt_other').checked == false)) {
		alert('You must choose at least one topic of interest.');
		return false;
	}
	if ((document.getElementById('opt_other').checked == true) &&
		(document.getElementById('opt_other_text').value == '')) {
		alert('You must enter a description for \'other\'');
		return false;
	}
	if (document.getElementById('name').value == '') {
		alert('You must enter your name before you can submit this form');
		return false;
	}
	if (document.getElementById('email').value == '') {
		alert('You must enter your email address before you can submit this form');
		return false;
	} else {
		var regex = /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/;
		if (!regex.test(document.getElementById('email').value)) {
			alert('That email address appears to be invalid.  Please enter a valid address.');
			return false;
		}
	}
	if ((document.getElementById('contact_none').checked == false) && 
		(document.getElementById('contact_mail').checked == false) && 
		(document.getElementById('contact_phone').checked == false) && 
		(document.getElementById('contact_email').checked == false)) {
		alert('You must select a contact option before you can continue');
		return false;
	}
}
function trip_other() {
	if (document.getElementById('opt_other_text').value != '') {
		document.getElementById('opt_other').checked = true;
	}
}