Button (onClick)

Good morning,

Is it possible to add a similar function to an “OnClick event” button?

Or what needs to be done to make it work?

(function(){
    var css = {};
	
    if(fieldname24 > 1) {
        
        css['width'] = (fieldname24 * 4) + 'px';
    } else {
        
        css['width'] = '400px';
    }
    jQuery('#fbuilder .my-class').each(function(){jQuery(this).css(css);});
})();