$(document).ready(function(){

    //get the height and width of the page
    var window_width = $(window).width();
    var window_height = $(window).height();

    //vertical and horizontal centering of modal window(s)
    /*we will use each function so if we have more then 1
    modal window we center them all*/
    $('.modal').each(function(){

        //get the height and width of the modal
        var modal_height = $(this).outerHeight();
        var modal_width = $(this).outerWidth();

        //calculate top and left offset needed for centering
        var top = (window_height-modal_height)/2;
        var left = (window_width-modal_width)/2;

        //apply new top and left css values
        $(this).css({'top' : top , 'left' : left});

    });

        $('a[name=modal]').click(function(){

              //get the id of the modal window stored in the name of the activating element
              var modal_id = $(this).attr('class');

              //use the function to show it
              show_modal(modal_id);

        });

        $('.close').click(function(){

            //use the function to close it
            close_modal();

        });

    });

    //THE FUNCTIONS

    function close_modal(){

        //hide the mask
        $('#mask').fadeOut(500);

        //hide modal window(s)
        $('.modal').fadeOut(500);

    }
    function show_modal(modal_id){

        //set display to block and opacity to 0 so we can use fadeTo
        $('#mask').css({ 'display' : 'block', opacity : 0});

        //fade in the mask to opacity 0.8
        $('#mask').fadeTo(500,0.8);

         //show the modal window
        $('.'+modal_id).fadeIn(500);

    }