function gal1(id_lay) {

 myWidth= document.body.offsetWidth;
 myHeight= document.body.offsetHeight;

  document.getElementById(id_lay).style.width=myWidth+"px";
  document.getElementById(id_lay).style.height=myHeight+"px";
      document.getElementById(id_lay).style.display='block';

}


function gal2(id_lay) {
    document.getElementById(id_lay).style.display='none';
}