I just rescued a baby Robin!?

It seems fairly old kinda just about ready to fly age.. but it has been sitting on my front porch for 2 days just sitting and chirping I was so worried I took it inside tonight its in a large box with a light over it so it wont get cold an there's a peace of an old towel and some stuffing from a shredded pillow in my craft room .....what should I do? ... it let me hold it strangely enough any advice is appreciated