$(document).ready(function() {    
  
    //select all the a tag with name equal to modal  
    $('a[name=modal]').click(function(e) {  
        //Cancel the link behavior  
        e.preventDefault();  
       //Get the A tag  
      var id = $(this).attr('href');  
     
      //Get the screen height and width  
       var maskHeight = $(document).height();  
       var maskWidth = $(window).width();  
     
       //Set height and width to mask to fill up the whole screen  
        $('#mask').css({'width':maskWidth,'height':maskHeight});  
         
       //transition effect       
       $('#mask').fadeIn(500);      
      $('#mask').fadeTo("slow",0.9);    
     
       //Get the window height and width  
        var winH = $(window).height();  
       var winW = $(window).width();  
               
       //Set the popup window to center  
       $(id).css('top',  winH/2-$(id).height()/2);  
        $(id).css('left', winW/2-$(id).width()/2);  
      
        //transition effect  
         $(id).fadeIn(2000);   
      
    });  
      
    //if close button is clicked  
     $('.window .close').click(function (e) {  
       //Cancel the link behavior  
      e.preventDefault();  
        $('#mask, .window').hide();  
  });       
     
    //if mask is clicked  
    $('#mask').click(function () {  
        $(this).hide();  
       $('.window').hide();  
   });           
      
});