function f_show_hide (content_id){
//$('#'+content_id).slideToggle('slow');
if($('#'+content_id).is(":visible")){
$('#'+content_id).hide();
$('#wrapper_headlines').show();
} else {
$('#'+content_id).show();
$('#wrapper_headlines').hide();
}
}
/* Toggle between adding and removing the "responsive" class to topnav when the user clicks on the icon */
function f_menu() {
var x = document.getElementById("myTopnav");
if (x.className === "topnav") {
x.className += " responsive";
document.getElementById("logo_wrapper").style.display = 'none';
document.getElementById("login_button_wrapper").style.display = 'none';
$("#icon").text('X');
$("#icon").addClass('icon_white');
} else {
x.className = "topnav";
document.getElementById("logo_wrapper").style.display = 'block';
document.getElementById("login_button_wrapper").style.display = 'block';
$("#icon").text('☰');
$("#icon").addClass('icon');
$("#icon").removeClass('icon_white');
}
}