replacing a ceiling fan light switch  

My brother took my mothers fan apart and removed the bad light switch. My mother is tired of waiting on my brother to put the new switch in and putfan back together. she asked me. I took one end of the switch and tired it in with the white wires from the lights, and I took the other wire of the switch and tied it into the black wires also from the lights. But, everytime I pull the switch, I pop the circuit breaker. Help.