A drainage system is provided for draining liquid accidentally spilled on a casing having a plurality of pushbuttons on a surface of the casing. The drainage system for a pushbutton casing may comprise a liquid collecting receptacle, a counter-bore, and a drainage exit. The counter-bore may have a sidewall. The liquid collecting receptacle may be operatively interfacing the casing. The drainage exit may be disposed on the sidewall of the counter-bore. An end opening of the counter-bore may be in connection with a drainage exit. The end opening of the counter-bore may be disposed to allow liquid entering the drainage exit out of the end opening of the counter-bore.