// Browser Window Size and Position
// copyright Stephen Chapman, 3rd Jan 2005, 8th Dec 2005
// you may copy these functions but please keep the copyright notice as well
function pageWidth() {
	return window.innerWidth != null ? window.innerWidth : document.documentElement && 
	document.documentElement.clientWidth ? document.documentElement.clientWidth : document.body != null ? document.body.clientWidth : null;
} 
	
function pageHeight() {
	return  window.innerHeight != null? window.innerHeight : document.documentElement && 
	document.documentElement.clientHeight ?  document.documentElement.clientHeight : document.body != null? document.body.clientHeight : null;
}

function posLeft() {
	return typeof window.pageXOffset != 'undefined' ? window.pageXOffset :document.documentElement && 
	document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft ? document.body.scrollLeft : 0;
}

function posTop() { 
	return typeof window.pageYOffset != 'undefined' ?  window.pageYOffset : document.documentElement && 
	document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop ? document.body.scrollTop : 0;
} 

function posRight() {
	return posLeft()+pageWidth();
} 

function posBottom() {
	return posTop()+pageHeight();
}

function hide_upload_form() {
	var upload_form = document.getElementById('upload_form');
	var upload_form_shadow = document.getElementById('upload_form_shadow');
	upload_form.style.visibility = 'hidden';
	upload_form_shadow.style.visibility = 'hidden';
	form_shown = 0;
}

var form_shown = 0;

function show_upload_form(parkid) {
	if (form_shown)
		return;
	var upload_form = document.getElementById('upload_form');
	var upload_form_shadow = document.getElementById('upload_form_shadow');
	upload_form.style.left = (pageWidth() / 2 - upload_form.offsetWidth / 2) + 'px';
	upload_form.style.top = (pageHeight() / 2 - upload_form.offsetHeight / 2) + posTop() + 'px';
	upload_form_shadow.style.left = (pageWidth() / 2 - upload_form.offsetWidth / 2) + 8 + 'px';
	upload_form_shadow.style.top = (pageHeight() / 2 - upload_form.offsetHeight / 2) + posTop() + 8 + 'px';
	
	// ajax post to get form
	if (window.XMLHttpRequest) {
		http = new XMLHttpRequest();
	} else if (window.ActiveXObject) {
		http = new ActiveXObject("Microsoft.XMLHTTP");
	}
	
	http.onreadystatechange = function() {
		if (http.readyState == 4) { // only if http is "loaded"
			if (http.status == 200) { // only if "OK"
				upload_form.innerHTML = http.responseText;
				upload_form.style.visibility = 'visible';
				upload_form_shadow.style.visibility = 'visible';
			} else {
				upload_form.innerHTML=" AHAH Error:\n"+ http.status + "\n" +http.statusText;
			}
		}
	};
		
	var parameters = "parkid="+parkid;
	http.open("POST", "upload_image_form.php", true);
	http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http.setRequestHeader("Content-length", parameters.length);
    http.setRequestHeader("Connection", "close");
	http.send(parameters);
}