how to do open a link in a open window from menu bar? [closed]

Please add below code to bottom of your functions.php, I have replaced with your menu item ID

function lidget_popup_link() {
?>
<script type="text/javascript">
    jQuery(window).load(function() {
        var width = "680", /* Enter popup window width here */
            height = "480", /* Enter popup window height here */
            menuItem = "menu-item-140", /* Enter menu item ID */
            target = "#"+menuItem+" a",
            hrefVal = jQuery(target).attr("href")
        ;
        jQuery(target).attr({
            "href" : "#",
            "onclick" : "window.open('"+hrefVal+"','','width="+width+",height="+height+",scrollbars=no,resizable=no,location=no,menubar=no,toolbar=no')"
        });
    });
</script>
<?php
}
add_action('wp_head', 'lidget_popup_link');

function lidget_call_jquery() {
    wp_enqueue_script('jquery');
}
add_action('wp_enqueue_scripts', 'lidget_call_jquery');
?>

For details please follow wordpress.org support

OUTPUT (contact page open in pop up):

enter image description here