function createRequestObject(){
	var objRequest;  // Request object

    if (window.XMLHttpRequest) { 
		objRequest = new XMLHttpRequest();
	}else{
		objRequest = new ActiveXObject("Microsoft.XMLHTTP");  // For IE
	}
	return objRequest;
}
	
var http = createRequestObject(); 

function getVideoListing(topicId){
//	 alert('At getVideoListing with topicID: ' + topicId);
	http.open('get', 'http://www.greenmaking.com/pages/video_listing_request.php?action=getVideoList&topicId=' + topicId);
	http.onreadystatechange = handleVideoListing; 
	http.send(null);
}

function catchKey(evt,keyphrase) {
// alert('Function catchKey');
	evt = (evt) ? evt : ((window.event) ? window.event : null);
	if (evt.type == 'keydown')
		if (evt.keyCode == 13) {
			searchVideoListing(keyphrase);
	}
}

function searchVideoListing(keyphrase){
//	alert('searchVideoListing reached.');
//	alert('The keyphrase is ' + keyphrase);
	http.open('post', 'http://www.greenmaking.com/pages/site-administration/video_listing_request.php',false);
	http.onreadystatechange = handleVideoListing; 
	http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	http.send('action=searchVideoList&keyphrase='+encodeURI(keyphrase));
}

function handleVideoListing(){
	if(http.readyState == 4){
		var strResponse = http.responseText;
		switch(http.status) {
//			case 200:
//				document.getElementById('video-listing-area').innerHTML = strResponse + http.status;
			case 404:
				alert('Error: Not Found. The requested URL video_listing_request.php could not be found.');
				break;
			case 500:
				handleErrFullPage(strResponse);
				break;
			default:
// alert('server returned');
//				document.getElementById('video-listing-area').innerHTML = strResponse + http.status;
				document.getElementById('video-listing-area').innerHTML = strResponse;
		};
	}
}

function handleErrFullPage(strIn) {
        var errorWin;

        try {
                errorWin = window.open('', 'errorWin');
                errorWin.document.body.innerHTML = strIn;
        }
        catch(e) {
                alert('An error occurred, but the error message cannot be' +
                        ' displayed because of your browser\'s pop-up blocker.\n' +
                        'Please allow pop-ups from www.greenmaking.com.');
        }
}

function doNothing() {
	return;
}