JQuery: prop("disabled", false) when the DropZone js field !== 0

Question

I use DropZone js for file uploads,I have a custom button for processQueue() button to process the files manually after uploading.

if (myDropzone.files.length == 0){
    $('#upload_dropzone').prop("disabled", true);
} else if(myDropzone.getRejectedFiles().length > 0) {
    alert("The attached file is invalid");
} else {
    $('#upload_dropzone').prop("disabled", false);
}


$('#upload_dropzone').on('click',function(e){
    e.preventDefault();
    myDropzone.processQueue();
});

What I want to do is:

If the dropzone field is NOT empty, then remove the disabled attribute. After selecting the files the button is still disabled