Interfacing switch with AT89S52

I have connected switch and LED to AT89S52. I want to turn ON LED when switch is ON and turn of LED when switch is OFF. I have written code in Keil for interfacing switch but the problem is when switch is ON, LED doesn't turn ON and when switch is OFF, LED doesn't turn OFF. I measured the output voltage of pin P0.1 It show zero volt. I am trying to solve this problem from last 4-5 hours but nothing happening

Please check out these codes, wiring and help me
Interfacing switch with AT89S52