//The following code is snagged from http://www-128.ibm.com/developerworks/web/library/wa-ajaxintro1.html
//It does the cross-browser stuff (i.e., IE compatibility)

/* Create a new XMLHttpRequest object to talk to the Web server */
var xmlHttp = false;
/*@cc_on @*/
/*@if (@_jscript_version >= 5)
try {
  xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
  try {
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  } catch (e2) {
    xmlHttp = false;
  }
}
@end @*/

if (!xmlHttp && typeof XMLHttpRequest != 'undefined') {
  xmlHttp = new XMLHttpRequest();
}

//End snag from http://www-128.ibm.com/developerworks/web/library/wa-ajaxintro1.html

//Hide the pre-req box if there's nothing to put in it
function showOrHidePreReq() {
	/*var i = 1;
	var show_prereq_box = false;
	for (i = 1; i <= 8; i++) {
		var this_div = document.getElementById('prereq' + i);
		if (this_div && this_div.childNodes.length > 0) {
			show_prereq_box = true;
		}
	}
	if (document.getElementById('prereq_explain')) {
		var prereq_box = document.getElementById('prereq_explain');
		if (show_prereq_box) {
			if (prereq_box.style.display != 'block') {
				prereq_box.style.display = 'block';
				AJS.fx.fadeIn(prereq_box);
			}
		} else {
			AJS.fx.fadeOut(prereq_box, {
				duration: 500,
				onComplete: function() {prereq_box.style.display = 'none';}
			});
			
		}
	}*/
}

function updateCommentsPrereqs() {
    var searches = {}
    $course_ids = $('.prereq').prev().each(function(index, menu) {
        if (menu.value != "") searches["id"+(index+1)] = menu.value;
    });
    
    
    $.getJSON('course_comment_prereq.php', searches, function(data) {
        for (course in data) {
            menu = $('select[@value='+course+']')[0];
            box = $(menu).next()[0];
            show_prereqs(box, data[course]['comments'], data[course]['prereq'], data[course]['tours']);
        }
    });
    
    //Clear the box for empty ones
    $('select[@value=]').next().html('');
    return searches;
}

function show_prereqs(dest, comments, prereqs, tours) {
    if (comments) comments = "<div class=\"course_comment\">"+comments+"</div>";
    if (prereqs) prereqs = "<div class=\"course_prereq\"><span class=\"prereq-header\">Prerequisites:</span> "+prereqs+"</div>";
    if (tours) tours = "<div calss=\"course_comment\">"+tours+"</div>";
    if (comments || prereqs || tours)
        $(dest).html(comments + prereqs + tours);
    else
        $(dest).empty();
}

function toggleTranscriptUploader(num) {
	if (document.getElementById('delete-'+num).checked == true) {
		document.getElementById('replace-'+num).disabled = true;
	} else {
		document.getElementById('replace-'+num).disabled = false;
	}
}

function fancifyInstructionLinks() {
	var links = document.getElementsByTagName('A');
	
	function makeShower(url) { //Necessary due to static scoping of variables
	 	return function () { GB_showCenter('', url, 500, 700); };
	}
	
	for (var i = 0; i < links.length; i++) {
		if (links[i].className && links[i].className == 'instructions') {
			var link = links[i];
			var old_href = link.href;
			var new_href = link.href.replace('page=instructions', 'page=instructions-embedded');

			link.onclick = makeShower(new_href);
			link.href = "#";
			link.target = "";
		}
	}
}

function fancy_saver () {
	var new_html = '<img src="media/loading-white-small.gif" alt="Loading"> Your data is being saved. This may take up to 10 seconds.';
	setTimeout("document.getElementById('after_submit').innerHTML = '" + new_html + "'", 200);
}



//Do preparation work
window.onload = function() {
 fancifyInstructionLinks();
 showOrHidePreReq();
}