function SetTabValue() {
    document.getElementById('tab').value = "photography";
}

function ChangeTab(tab) {
    switch (tab)
    {
        case 'news':
        default:
            document.getElementById('tab').value = "news";
            document.getElementById('blog-news').style.display = "block";
            document.getElementById('blog-photography').style.display = "none";
            document.getElementById('blog-design').style.display = "none";
            document.getElementById('menu-news').className = "menu";
            document.getElementById('menu-photography').className = "menu-link";
            document.getElementById('menu-design').className = "menu-link";
            break;
        case 'photography':
            document.getElementById('tab').value = "photography";
            document.getElementById('blog-news').style.display = "none";
            document.getElementById('blog-photography').style.display = "block";
            document.getElementById('blog-design').style.display = "none";
            document.getElementById('menu-news').className = "menu-link";
            document.getElementById('menu-photography').className = "menu";
            document.getElementById('menu-design').className = "menu-link";
            break;
        case 'design':
            document.getElementById('tab').value = "design";
            document.getElementById('blog-news').style.display = "none";
            document.getElementById('blog-photography').style.display = "none";
            document.getElementById('blog-design').style.display = "block";
            document.getElementById('menu-news').className = "menu-link";
            document.getElementById('menu-photography').className = "menu-link";
            document.getElementById('menu-design').className = "menu";
            break;
    }
}

function EditPost(num) {
    var password = prompt("Password required to edit this blog entry.", "");
    password = hex_md5(password);
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.onreadystatechange = function(){
        if (xmlHttp.readyState == 4)
        { 
            alert(xmlHttp.responseText);
        }    
    }
    xmlHttp.open("GET", "edit.php?id=" + num + "&password=" + password, true);
    xmlHttp.send(null);
}

function DeletePost(num) {
    var password = prompt("Password required to delete this blog entry.", "");
    password = hex_md5(password);
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.onreadystatechange = function(){
        if (xmlHttp.readyState == 4)
        {
            if (xmlHttp.responseText.substring(0, 9) == "Incorrect")
            {
                alert("Incorrect password.");
                return;
            } else if (xmlHttp.responseText.substring(0, 5) != "Error") {
                var category = "blog-" + document.getElementById('tab').value;
                document.getElementById(category).innerHTML = xmlHttp.responseText;
                //alert(xmlHttp.responseText);
            } else {
                alert("An error has occurred.");
            }
        }    
    }
    xmlHttp.open("GET", "delete.php?id=" + num + "&password=" + password, true);
    xmlHttp.send(null);
}

function GenerateVideoString() {
    var filename = document.getElementById("txtFilename").value;
    var width = document.getElementById("txtWidth").value;
    var height = document.getElementById("txtHeight").value;
    var str = "%1%" + filename + "%2%" + width + "%3%" + height + "%4%" + filename + "%5%" + filename + "%6%";
    alert("Copy and paste the following string into your blog entry:\n" + str);
}