jQuery - Execute scripts based on screen size

Just use the following:

if($(window).width() >= 1024){
    //your code here
}

This works, but remember to put the script at the end of your page rather than at the beginning, otherwise you'll end up having mixed results. I'd also avoid using it inside a document.ready() event if you're planning to use it to apply styles of any sort as there might be a slight but noticeable delay in applying said styles.

You might also consider a library like https://github.com/paulirish/matchMedia.js/

if (matchMedia('only screen and (max-width: 480px)').matches) {
  // smartphone/iphone... maybe run some small-screen related dom scripting?
}

You can use $(window).width()

if($(window).width() >= 1024){
  // do your stuff
}

Demo ---> http://jsfiddle.net/fh2eC/1/

If you want to check width size after windows is resized then:

$(window).resize(function() {
    if( $(this).width() > width ) {
        // code
    }
});