Well, what are your temps? For a baby that young, the basking spot should be from 110-115 degrees, with the cool side around 85. If its too cold, they cant digest their food properly, thus they won't eat. Do you also have a UVB light (long, skinny flourescent tube)? How big the tank you have him in? A little more info about your setup will help us try and figure out whats wrong with him 
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~Melissa~
1.3 Leopard geckos
1.0 Bearded dragon
1.0 Hog Island Boa
0.0.1 crested gecko
1.0 Ferret
0.1 Chinchilla
1.0 Chinese Praying Mantis
Melissas Menagerie