if (document.images) {
	var img = new Array();
	//enter images into the array
	img[0] = 'images/nav_about_0.gif';
	img[1] = 'images/nav_about_1.gif';
	img[2] = 'images/nav_directory_0.gif';
	img[3] = 'images/nav_directory_1.gif';
	img[4] = 'images/nav_news_0.gif';
	img[5] = 'images/nav_news_1.gif';
	img[6] = 'images/nav_programs_0.gif';
	img[7] = 'images/nav_programs_1.gif';
	img[8] = 'images/nav_ired_0.gif';
	img[9] = 'images/nav_ired_1.gif';
	img[10] = 'images/nav_events_0.gif';
	img[11] = 'images/nav_events_1.gif';
	img[12] = 'images/nav_members_0.gif';
	img[13] = 'images/nav_members_1.gif';
	img[14] = 'images/nav_resources_0.gif';
	img[15] = 'images/nav_resources_1.gif';
	img[16] = 'images/nav_government_0.gif';
	img[17] = 'images/nav_government_1.gif';
	
	var im = new Array();
	
	for (var i = 0; i < img.length; i++) {
		im[i] = new Image();
		im[i].src = img[i];	
	}
}

function toggleImg(imageName, num) {
	if (document.images) {
		document.images[imageName].src = im[num].src;
	}
}

function resolution() {
		document.write("<input name='screenresolution' type='hidden' value='" + screen.width + "x" + screen.height + "' />");
	}
	
function GetSelectedItem() {
	chosen = ""
	len = document.registration.seminartype.length
	
	for (i = 0; i <len; i++) {
	if (document.registration.seminartype[i].checked) {
		chosen = document.registration.seminartype[i].value
		}
	}
		
		if (chosen == "IHEA Combustion Seminar") {
			document.registration.PaymentAmount[0].disabled=false;
			document.registration.PaymentAmount[1].disabled=false;
			document.registration.PaymentAmount[2].disabled=true;
			document.registration.PaymentAmount[3].disabled=true;
			return;
		}
		else {
			document.registration.PaymentAmount[0].disabled=true;
			document.registration.PaymentAmount[1].disabled=true;
			document.registration.PaymentAmount[2].disabled=false;
			document.registration.PaymentAmount[3].disabled=false;
			return;
		}
	}
	
function BlankHotel() {
	if (document.registration.notneeded.checked) {
		document.registration.room[0].disabled=true;
		document.registration.room[1].disabled=true;
		document.registration.room[2].disabled=true;
		document.registration.requests[0].disabled=true;
		document.registration.requests[1].disabled=true;
		document.registration.requests[2].disabled=true;
		document.registration.guests.disabled=true;
		document.registration.arrivaldate.disabled=true;
		document.registration.departuredate.disabled=true;
		return;
	}
	else {
		document.registration.room[0].disabled=false;
		document.registration.room[1].disabled=false;
		document.registration.room[2].disabled=false;
		document.registration.requests[0].disabled=false;
		document.registration.requests[1].disabled=false;
		document.registration.requests[2].disabled=false;
		document.registration.guests.disabled=false;
		document.registration.arrivaldate.disabled=false;
		document.registration.departuredate.disabled=false;
		return;
	
	}
}