function setCookie( name, value, expiredays ) { 
    var todayDate = new Date(); 
        todayDate.setDate( todayDate.getDate() + expiredays ); 
        document.cookie = name + "=" + escape( value ) + "; path=/; expires=" + todayDate.toGMTString() + ";" 
    } 

function closeWin(id) { 
    if ( document.forms[id].chkbox.checked ){ 
        setCookie( id, "done" , 1 ); 
    } 
    document.getElementById(id).style.visibility = "hidden";
}