var mousedown = false;
		var markAvailable = true;
		var availabilityHidden = true;
		
	
		function markAll (element, checked) {
			objElement = document.getElementById(element);
			aryInput = objElement.getElementsByTagName("input");
			
			for (var i = 0; i < aryInput.length; i++) {
				aryInput[i].checked = checked;
				cell = aryInput[i].parentNode;
				if (checked == true) {
					cell.style.backgroundColor = 'green';
				} else {
					cell.style.backgroundColor = 'red';
				}

			
			}
		}
			
		function reverseAvailableText() {
			if (markAvailable == true) {
				return "Multi-Mark as Unavailable";
			} else {
				return "Multi-Mark as Available";
			}
		}
		
		function onclickHour(caller) {
			
			cell = caller.parentNode;
				
			if (caller.checked == true) {
				cell.style.backgroundColor = 'green';
			} else {
				cell.style.backgroundColor = 'red';
			}
		}
		
		function mouseoverHour(caller) {
		
			if (mousedown == true) {

				input = caller.getElementsByTagName("input")[0];
				if (markAvailable == true) {
					input.checked = true;
					caller.style.backgroundColor = 'green';
				} else {
					input.checked = false; 
					caller.style.backgroundColor = 'red';
				}
			}
		
		}
		
		function showHideAvailability () {
		
			objHeader = document.getElementById('availability_header');
			objContent = document.getElementById('availability_content');
		
			if (availabilityHidden == true) {
				objHeader.style.display = '';
				objContent.style.display = '';
				availabilityHidden = false;
				return "Hide Member Availability";
				
			} else {
				objHeader.style.display = 'none';
				objContent.style.display = 'none';
				availabilityHidden = true;
				return "Show Member Availability";
				
			} 
			
				
		}


var xmlhttp = false;

if (window.XMLHttpRequest) {
	xmlhttp = new XMLHttpRequest();
	xmlhttp.overrideMimeType('text/xml');
} else if (window.ActiveXObject) {
	xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}


function buildAvailabilityChart() {

	var offset = document.getElementById('sel_timezoneoffset').value;
	var qry = "action=build_form&offset="+offset;
	var url = "availability.php?"+qry;
	xmlhttp.open('GET',url,true);
	xmlhttp.onreadystatechange = getAvailabilityChart;
	xmlhttp.send(null);

}

function getAvailabilityChart() {

	if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
		document.getElementById('AvailabilityChart').innerHTML = xmlhttp.responseText;
	} else {
		document.getElementById('AvailabilityChart').innerHTML = '<br/>Building Availability Chart...<br/><br/>';
	}

}

function setupEvents() {

	// add onchange event to time zone select
	document.getElementById('sel_timezoneoffset').onchange = buildAvailabilityChart;

	// initial run
	buildAvailabilityChart();


}