var g_op;
var g_interval;

function click_1() {
        var elt = document.getElementById("foobar1");
        elt.setAttribute("label", "BOOM !");
}

function click_2() {
        var elt = document.getElementById("foobar2");
        elt.setAttribute("style", "-moz-appearance: none; background-color: red;");
}


function click_3() {
        alert(4 + 2);
}

function click_4() {
        alert("4" + "2");
}

function click_5() {
        try {
                var elt = document.getNimp();
        } catch (e) {
                alert(e);
        }
}

function up_opacity() {
        try {
                var elt = document.getElementById("img");
                g_op += 0.02;
                elt.setAttribute("style", "-moz-opacity: " + g_op + ";");
                if (g_op == 1) {
                        clearInterval(g_interval);
                }
        } catch (e) {
                alert(e);
        }
}


function click_6() {
        g_op = 0;
        try {
                g_interval = setInterval(up_opacity, 100);
        } catch (e) {
                alert(e);
        }
}