function iframe(id) {
 if(/MSIE/.test(navigator.userAgent))  {
    document.getElementById("cont_" + id).style.display='block';
    document.getElementById("if_" + id).style.width = document.getElementById("tab_" + id).offsetWidth + 'px';
    document.getElementById("if_" + id).style.height = document.getElementById("tab_" + id).offsetHeight + 'px';
    }
    document.getElementById("cont_" + id).style.display='block';
}

function ifHiddenOrVisible(){
    if (document.getElementById('cont_1').style.display == 'block')
        document.getElementById('selectLayer').style.visibility = 'hidden';
    if (document.getElementById('cont_3').style.display == 'block')
        document.getElementById('selectLayer').style.visibility = 'hidden';
    else document.getElementById('selectLayer').style.visibility = 'visible'; 
}