Show button "Open in Google Maps"

Great!!!

I change a little, following this:

Here’s the info on Google’s URL:

http://maps.google.com/maps?z=12&t=m&q=loc:38.9419+-78.3020

z is the zoom level (1-20)
t is the map type (“m” map, “k” satellite, “h” hybrid, “p” terrain, “e” GoogleEarth)
q is the search query, if it is prefixed by loc: then google assumes it is a lat lon separated by a +

And this is my code to help who need it

<?php

add_action('geodir_after_social_sharing_buttons' , 'buttonmap', 10);
function buttonmap(){
global $post, $wp_query, $preview, $geodirectory;
$postid = $wp_query->post->ID;
$address= geodir_get_post_meta($postid,'post_address',true); //address
$e_add = str_replace(' ', '+', $address); // + in space eg road+street+23

$lat= geodir_get_post_meta($postid,'post_latitude',true); //lat
$lon= geodir_get_post_meta($postid,'post_longitude',true); //lon
//echo $e_add.$lat.$lon;

echo "<a href="http://maps.google.com/maps?z=12&t=m&q=loc:".$lat."+".$lon."" target="_blank"> Mostra en Google Maps</a>";
}