Question

Any idea how I can make a function be called only once using .resize, and then have it permanently cancelled or disabled?

$(window).resize(function () {
    if ($(window).width() < 800) {
        size = true;
        mob();
    }
});

UPDATE: Great stuff, thanks sdespont – got it to work with on/off:

$(window).on('resize',function () {
            if ($(window).width() < 800){
                    agent = true;
                    mob();
            }
            });

then turn off the resize function once the condition is met:

$(window).off('resize');

Answer 1

Use one function http://api.jquery.com/one/

$(window).one('resize',function () {
    if ($(window).width() < 800){
        size = true;
        mob();
    }
});
$(window).trigger('resize');

Or on/off functions http://api.jquery.com/on/

$(window).on('resize',function () {
    if ($(window).width() < 800){
        size = true;
        mob();
    }
});

$(window).trigger('resize').off('resize');