code: function( from, to, unit ) {
  		var self = this,
  			fx = jQuery.fx;
  
  		this.startTime = fxNow || createFxNow();
  		this.end = to;
  		this.now = this.start = from;
  		this.pos = this.state = 0;
  		this.unit = unit || this.unit || ( jQuery.cssNumber[ this.prop ] ? "" : "px" );
  
  		function t( gotoEnd ) {
  			return self.step( gotoEnd );
  		}
  
  		t.queue = this.options.queue;
  		t.elem = this.elem;
  		t.saveState = function() {
  			if ( self.options.hide && jQuery._data( self.elem, "fxshow" + self.prop ) === undefined ) {
  				jQuery._data( self.elem, "fxshow" + self.prop, self.start );
  			}
  		};
  
  		if ( t() && jQuery.timers.push(t) && !timerId ) {
  			timerId = setInterval( fx.tick, fx.interval );
  		}
  	}
docs: Start an animation from one number to another