Issue with Turning LED ON-OFF with Switch input

Other Parts Discussed in Thread: MSP430F6638

Hello, This is my First Post to TI Community......I am a Beginner in the Field of Microcontroller and I am using MSP-TS430PZ100USB Launch Pad with MSP430F6638 Controller

I am Writing a Program that will Turn the LED ON until a Switch is Pressed.

My Problem is, I am not able to Turn the LED completely off. I mean LED Remain ON all Time and If i Press the Switch it only Increases the Intensity of LED and after I release the switch it step back to it initial condition (Dim the LED's Intensity)

I am using a Pull Up Network to Read the Switch Input

My Code is  :

#include <msp430.h> 


#define SW BIT1
#define LED BIT0

int main(void) {
    WDTCTL = WDTPW | WDTHOLD;           // Stop WatchDog timer
    P1OUT &= ~LED;                                        //Make LED off Initially
    P1DIR |= LED;                                             //Set Direction of LED as Output

    while(1){
    	while((P1IN & SW) == 1);                        //Wait Till the Switch is Pulled Up
    	P1OUT |= LED;                                        //Turn on the LED  (Active High)
    	while((P1IN & SW) == 0);                       //Wait Till the Switch is Pulled Down i.e; until Switch is Pressed
    	P1OUT &= ~LED;                                    //  Turn off the LED

    }
	return 0;
}

Please help me.