var vpage = 1;
var activeVideoIndex = 0;

function v_next() {
    if (vpage<=(vpages-4)) {
        vcontainer = document.getElementById("videoiconcontainer");
        vcontainer.style.marginLeft = (vcontainer.style.marginLeft.replace("px", "") - 66) + "px";
        vpage = vpage + 1;    
    }
}

function v_prev() {
    if (vpage>1) {
        vcontainer = document.getElementById("videoiconcontainer");
        vcontainer.style.marginLeft = (parseInt(vcontainer.style.marginLeft.replace("px", "")) + 66) + "px";
        vpage = vpage - 1;    
    }
}

function makeActive(index) {
    document.getElementById("vimage"+activeVideoIndex).className=""; 
    document.getElementById("vimage"+index).className="active";
    activeVideoIndex = index;
    makeRequest(videos[index].id);    
}

function makeRequest(video_id) {
                                   
    var http_request = false;
    
    var url = "/mods/get_video_source.php";
    
    var vars = "id=" + video_id;
    
    if (window.XMLHttpRequest) { // Mozilla, Safari, ...
    
        http_request = new XMLHttpRequest();
        
    } else if (window.ActiveXObject) { // IE
    
        try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
        try {
            http_request = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {}
        }
        
    }
    
    if (!http_request) {
        alert('There is no possibility to send request. Check if java turn on in your browser.');
        return false;
    }
    
    http_request.onreadystatechange = function() { getContents(http_request); };    
    http_request.open('POST', url, true);
    http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    http_request.send(vars);
    
}

function getContents(http_request) {
    
    if (http_request.readyState == 4) {
        
        if (http_request.status == 200) {

            document.getElementById("videocontainer").innerHTML = http_request.responseText;
            
        } else {
            
            alert('Server Error.');   
            
        }
    }
}