jQuery Validator method for maximum filesize

jQuery.validator.filesize.js

jQuery.validator.addMethod("filesize_max", function(value, element, param) {
    var isOptional = this.optional(element),
        file;
    
    if(isOptional) {
        return isOptional;
    }
    
    if ($(element).attr("type") === "file") {
        
        if (element.files && element.files.length) {
            
            file = element.files[0];            
            return ( file.size && file.size <= param ); 
        }
    }
    return false;
}, "File size is too large.");