How to use ajax with blueprints in flask

I would like to define a global ajax function that I will use to unlock models in case a window closes unexpectedly.

@main.route('_unlockmodels)
def unlockmodels():
    .. unlock stuff ..
    return None

and then the actual ajax

function unlockModel() {
    $.ajax({
        type: "get",
        url: "main/_unlockmodels"
    }).done(function(data) {
        console.log('well see if your locks are gone', data, '<-- data?')
    });
}

Problem is, wherever I call this function from (in another blueprint) I get the following error

GET http://ift.tt/1HF1pCH

How to specify where I am currently calling from (or other way to fix this)?

I call the function from within my page's javascript like

window.onbeforeunload = unlockModel;