function setOpacity()
{
    //alert('set opacity');
    document.getElementById('basic-modal-content').style.visibility='visible';
    changeOpac('cnt_container', 40);
    changeOpac('cnt_click_and_lock', 40);
    changeOpac('basic-modal-content', 1000);
}


function unsetOpacity()
{
    //alert('unset opacity');
    document.getElementById('basic-modal-content').style.visibility='hidden';
    changeOpac('cnt_container', 1000);
    changeOpac('cnt_click_and_lock', 1000);
}

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

}