How to reenable event.preventDefault?

I have a web page which I have prevented the default action on all submit buttons, however I would like to re-enable default submit action on a button how can I do this?

I am currently preventing the default action using the following:

$("form").bind("submit", function(e){
e.preventDefault();
});

I have successfully done this using the following:

$(document).ready(function(){
$("form:not('#press')").bind("submit", function(e){
e.preventDefault();
});

But can I do this dynamically when the button is clicked?

You would have to unbind the event and either rebind to a separate event that does not preventDefault or just call the default event yourself later in the method after unbinding. There is no magical event.cancelled=false;

As requested

 $('form').submit( function(ev){

         ev.preventDefault();

         //later you decide you want to submit
         $(this).unbind('submit').submit()

  });

Either you do what redsquare proposes with this code:

function preventDefault(e) {
    e.preventDefault();
}
$("form").bind("submit", preventDefault);

// later, now switching back
$("form#foo").unbind("submit", preventDefault);

Or you assign a form attribute whenever submission is allowed. Something like this:

function preventDefault(e) {
    if (event.currentTarget.allowDefault) {
        return;
    }
    e.preventDefault();
}
$("form").bind("submit", preventDefault);

// later, now allowing submissions on the form
$("form#foo").get(0).allowDefault = true;