var alphapiu = setTimeout('', 1);

function alpha_piu(val_a) {
    val_piu = parseInt(val_a);
    window.parent.document.getElementById("imm_zoom").style.filter = 'alpha(opacity=' + val_piu + ')';
    window.parent.document.getElementById("imm_zoom").style.opacity = val_piu / 100;
    //if (val_piu <= 70) {
    //    window.parent.document.getElementById("didascalia_cont").style.filter = 'alpha(opacity=' + val_piu + ')';
    //    window.parent.document.getElementById("didascalia_cont").style.opacity = val_piu / 100;
    //}
    val_piu += 5;
    if (val_piu <= 100) {
        alphapiu = setTimeout("alpha_piu('" + val_piu + "')", 10);
    } else {
    clearTimeout(alphapiu);
        //alert("fine");
    }

}