<a href="#popup1" name="loadpopunder">Ссылка</a>

<td class="td1" onClick="document.location='#popup1'" name="loadpopunder"></td>

//Pop-under only once per browser session? (0=no, 1=yes)
//Specifying 0 will cause popunder to load every time page is loaded
var once_per_session=1

//No editing beyond here required
function get_cookie(Name) {
  var search = Name + "=", returnvalue = "";
  if (document.cookie.length > 0) {
    offset = document.cookie.indexOf(search)
    if (offset != -1) { // if cookie exists
      offset += search.length
      end = document.cookie.indexOf(";", offset);
      if (end == -1)
         end = document.cookie.length;
      returnvalue=unescape(document.cookie.substring(offset, end))
      }
   }
  return returnvalue;
}

function loadornot(){
    if (get_cookie('popunder')==''){
        loadpopunder();
        document.cookie="popunder=yes";
    }
}
function loadpopunder(){
var id = '#popup1';
	
		//Get the screen height and width
		var mask1Height = jQuery(document).height();
		var mask1Width = jQuery(window).width();
	
		//Set heigth and width to mask to fill up the whole screen
		jQuery('#mask1').css({'width':mask1Width,'height':mask1Height});
		
		//transition effect		
		jQuery('#mask1').fadeIn(1000);	
		jQuery('#mask1').fadeTo("slow",0.8);	
	
		//Get the window height and width
		var winH = jQuery(window).height();
		var winW = jQuery(window).width();
              
		//Set the popup window to center
		jQuery(id).css('top',  winH/2-jQuery(id).height()/2);
		jQuery(id).css('left', winW/2-jQuery(id).width()/2);
	
		//transition effect
		jQuery(id).fadeIn(2000);
}
jQuery(document).ready(function() {
    jQuery('a[name=loadpopunder]').click(function(e) {
        e.preventDefault();
        var id = jQuery(this).attr('href');
        loadpopunder(id); // вызываем по клику
    });
    jQuery('.window1 .close1').click(function (e) {
        e.preventDefault();
        jQuery('#mask1, .window1').hide();
    });
    jQuery('#mask1').click(function () {
        jQuery(this).hide();
        jQuery('.window1').hide();
    });
});