jQuery.easing = {

	easeinout: function(x, t, b, c, d) {
		if (t < d/2) return 2*c*t*t/(d*d) + b;
		var ts = t - d/2;
		return -2*c*ts*ts/(d*d) + 2*c*ts/d + c/2 + b;		
	}
};