Help me correct my LED blinking problem

unsigned short  i;
void main()
{

TRISB= 0xFF;
PORTB=0x00;
TRISD = 0x00; // PORTB as ouput
PORTD = 0x00; // Set port output as all 0's

while(1){
if(TRISB.F0==1) {  // Detect logical one to zero
for(i=0;i <50; i++){ //repeat 50 times
    PORTD.F0 = 0;   //switch on LED at PORTB pin 0
    delay_ms(150);  //short delay
    PORTD.F0 = 1;   //switch off LED
    delay_ms(150);
    }
 }

if(TRISB.F1==1) {  // Detect logical one to zero
for(i=0;i < 100; i++){ //repeat 100 times
    PORTD.F0 = 0;   //switch on LED at PORTB pin 0
    delay_ms(150);  //short delay
    PORTD.F0 = 1;   //switch off LED
    delay_ms(150);
    }
 }

if(TRISB.F2==1) {  // Detect logical one to zero
  for(i=0; i<1000; i++){ //repeat 1000 times
    PORTD.F0 = 0;   //switch on LED at PORTB pin 0
    delay_ms(150);  //short delay
    PORTD.F0 = 1;   //switch off LED
    delay_ms(150);
    }
 }
}
}