jquery.popupoverlay.js
function (el) {
            var genericCloseButton;

            if ($(el).data('popupoptions').closebuttonmarkup) {
                genericCloseButton = $(options.closebuttonmarkup).addClass(el.id + '_close');
            } else {
                genericCloseButton = '<button class="popup_close ' + el.id + '_close" title="Close" aria-label="Close"><span aria-hidden="true">×</span></button>';
            }

            if ($(el).data('popup-initialized')){
                $(el).append(genericCloseButton);
            }

        }
function (el) {
            var genericCloseButton;

            if ($(el).data('popupoptions').closebuttonmarkup) {
                genericCloseButton = $(options.closebuttonmarkup).addClass(el.id + '_close');
            } else {
                genericCloseButton = '<button class="popup_close ' + el.id + '_close" title="Close" aria-label="Close"><span aria-hidden="true">×</span></button>';
            }

            if ($(el).data('popup-initialized')){
                $(el).append(genericCloseButton);
            }

        }
function ( el ) { var genericCloseButton ; if ( $ ( el ) . data ( 'popupoptions' ) . closebuttonmarkup ) { genericCloseButton = $ ( options . closebuttonmarkup ) . addClass ( el . id + '_close' ) ; } else { genericCloseButton = '<button class="popup_close ' + el . id + '_close" title="Close" aria-label="Close"><span aria-hidden="true">×</span></button>'; } if ( $ ( el ) . data ( 'popup-initialized' ) ) { $ ( el ) . append ( genericCloseButton ) ; } }
Add-close-button method

@param {object} el - popup instance DOM node
Add - close - button method