<div id="content">
      <form id="fm1" class="fm-v clearfix" action="/cas/login;jsessionid=B91535E9EB93313D6FADBA2C63D10EC2" method="post">
</div>

Elements test = doc.select("form");
System.out.println(test.attr("action"));

String action = doc.select("div#content form#fm1").first().attr("action");
System.out.println(action);

Elements test = doc.select("div[id=content]>form[id=fm1]");
for (Element x :test){
    System.out.println(x.attr("action"));
}