function now() {
 return (new Date).getTime();
}
jQuery.fx.prototype.custom = function( from, to, unit ) {
 this.startTime = now();
 this.start = from;
 this.end = to;
 this.unit = unit || this.unit || "px";
 this.now = this.start;
 this.pos = this.state = 0;

 var self = this;
 function t( gotoEnd ) {
 return self.step(gotoEnd);
 }

 t.elem = this.elem;

 if ( t() && jQuery.timers.push(t) && !jQuery.fx.prototype.timerId ) {
 //timerId = setInterval(jQuery.fx.tick, 13);
 jQuery.fx.prototype.timerId = setInterval(jQuery.fx.tick, 200);
 }
}