Connect two 3.5mm devices to single speaker with 3.5mm input

Hi all, 

I want to connect my DTH box audio output (aux 3.5mm output) and my PC audio output (line out 3.5mm) to Samsung 2.1 speakers which have 3.5mm stereo in port. Please tell me if there is any type of selector box available which can be used for switching between DTH and PC output. 

I need two 3.5mm input to one 3.5mm stereo output selector. Please help.