jquery 2 forms one floating - php

Question

I have a page with login form (on click, login form slides dowm) and underneath I have a link for registering a new user. With click on 'register new' link, new form pops-up and after validating each field, the submit event doesn't work - because there is a login form too and jQuery tries to trigger submit event of the first form.
How to trigger this specific onsubmit event - for the second form? I tried to hide a first form, but it didn't work and then I try to disabled it, which doesn't work as well.
(forms on separate pages works fine - validated with PHP and JS)
I think this is an easy thing to do .. but I cannot figure out how to do. Till now I overcome this problem, but I really like to find out how to make it work.
Thanks.
Unfortunatelly .. none of this answers works ...
Here is the code:
<div id="loginFormContainer">
<h2 id="loginShow" class="myriad_pro_bold_condensed_italic">Login</h2>
<form name="login_form" action="<?php if(isset($action) && !empty($action)) echo $action; ?>" method="POST" id="login_form" >
<fieldset>
<label>Your name </label>
<input type="text" name="username" maxlength="30" id="username_login" value="" class="required" placeholder="Enter Your Name" />
<label>Your password </label>
<input type="password" name="password" maxlength="16" id="password_login" value="" class="required " placeholder="Enter Your Password" />
</fieldset>
<input type="hidden" name="token" value="<?php if(isset($token)) echo $token; ?>" />
<input type="submit" name="submit-login" id="submit_login" value="Login" />
</form>
<div class="small">Register | Forgotten Password</div>
<div class="error"></div>
</div>
And JS ... should work like: if on register click: register windows pops-up, if on login the login form should slide down.
Right now, both of them slides ...I can remove the login form if I want to register, but the submit button from register form doesn't work.
$("#login_form").hide();
$("#loginShow").click(function(){
$('form#login_form .error').remove();
$("#login_form").slideDown("slow");
$('form#login_form').on("submit", function(event) {
event.preventDefault();
//code validation and ajax submit
}); //end form submit
});
$('#register').click(function(e) {
//$('#loginShow').remove(); //form is removed, but submit event still doesn't work
//if I completely remove login form from php page, then works fine
e.preventDefault();
$('form#register_form').click(function(event) {
event.preventDefault();
//
}); //end form submit
});//end register floating
Oh, yes, one final detail: on Chrome works fine :S, not in FF (v.10)

Answer 1

$(":submit").click(function(e){
$(this).closest("form").submit();
return false;
});

Answer 2

Try this:
var secondForm = $('form').eq(1);
secondForm.trigger('submit');

Answer 3

Just give the second submit button an id.
<input type='submit' id='submit2'>
Now for trigerring validation bind onclick event to the submit2 id
$('#submit2').click(function(){
//logic goes here
});