To get this share button visit this url bellow:
And follow these instruction bellow:
1) Paste the code just below the <body> tag of your page.It enables your website to understand XFBML.Only paste this code once per page.
Script Preview on your facebook should be like this:
Change the Red color with your own Facebook id or you can get the code above directly in this url http://developers.facebook.com/tools.php?connect_wizard&wizard=share&app
Script Preview on your facebook should be like this:
<script src="http://static.ak.connect.facebook.com/js/api_lib/v0.4/FeatureLoader.js.php/en_GB" type="text/javascript"></script><script type="text/javascript">FB.init("9cdb7fde7e8f86905db4d4413100024f");</script><fb:comments> </fb:comments>
Note: Change the Red color with your own Facebook id or you can get the code above directly in this url http://developers.facebook.com/tools.php?connect_wizard&wizard=share&app
2) Select the style you'd like and the link you want to share. Then paste the code beneath into your site wherever you need it. You can use it more than once on a page but only do step 1) once.
3. Type the url you want to share in the box available
4. Then Paste the code in the body of your site
3. Type the url you want to share in the box available
4. Then Paste the code in the body of your site
For more explanation see the picture bellow: