jQuery(document).ready(function() {  
    
    if(jQuery.cookie('seen_popup') != 'has_seen'){
        scroll(0,0);    
        launchWindow('#dialog');
        jQuery.cookie('seen_popup','has_seen',{expires: 10000, path: '/'});
    }
    
    //if close button is clicked
    jQuery('.window .close, .window .opener').click(function () {
        jQuery('#mask').hide();
        jQuery('.window').hide();
    });         
    
    //if mask is clicked
    jQuery('#mask').click(function () {
        jQuery(this).hide();
        jQuery('.window').hide();
    });                 
    
});

function launchWindow(id) {
    //Get the screen height and width
    var maskHeight = jQuery(document).height();
    var maskWidth = jQuery(window).width();

    //Set heigth and width to mask to fill up the whole screen
    jQuery('#mask').css({'width':maskWidth,'height':maskHeight});

    //transition effect             
    jQuery('#mask').fadeIn(1000);        
    jQuery('#mask').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()));
    jQuery(id).css('left', winW/2 - (jQuery(id).width()/2));

    //transition effect
    jQuery(id).fadeIn(2000); 
}