/* nascondi gli elementi */

function scambio(id,type) {
    var nav = navigator.appName.toLowerCase();
    if (document.getElementById){
        var obj = document.getElementById(id);
        if (nav == 'microsoft internet explorer'){
            if(type == 1){
                obj.filters.alpha.opacity = 100;
            } else {
                obj.filters.alpha.opacity = 10;
            }
        } else {
            if(type == 1){
                    obj.style.opacity = 1;
                    obj.style.Mozopacity = 1.0;
                // obj.style.-khtml-opacity = 1.0;
            } else {
                obj.style.opacity = 0.1;
                obj.style.Mozopacity = 0.1;
                // obj.style.-khtml-opacity = 0.1;
            }
        }
    }
}

function opacity(id, opacStart, opacEnd, millisec) {
    //speed for each frame
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}