I made a side menu with these links:
<div id="menu_lat">
<a href="http://localhost:8080/sgf/form_proposta.php">Orçamentos</a>
<a href="relatorios.html">Relatórios</a>
<a href="proximos.html">Próximos Eventos</a>
<a href="chat.html">Chat</a>
</div>
When I open one of these, the content is opened in another div (which, in the first page, already has some content, which is an image):
<div id="conteudo">
<img src="img/foto_inicial.jpg">
</div>
How could I load the PHP file inside this layer when I click that link?