PIC12F629 gp4 problem

void main() {
  /* Project name:
     Detect low voltage
* Description:
     Car direction indicators
* Test configuration:
     MCU:             PIC12F629
     Dev.Board:       EasyPIC5
     Oscillator:      04.0000 MHz, Internal
     SW:              mikroC PRO for PIC
*/
unsigned char i;
bit oldstate;                       // Old state flag

{
CMCON = 0b00000111;                 // disable comparators
GPIO = 0b00000000;
TRISIO = 0b00010011;                     // gp0,gp1,gp4 = inputs, gp2, gp5= outputs

  while (1)
   {
   
    if (gpio.gp0 == 0)              // while GP0 = switch pressed
        {
        gpio.F2 =1;
        delay_ms(500);
        gpio.F2 = 0;
        delay_ms(500);
        }

     if (gpio.gp1 == 0)              // while GP1 = switch pressed
        {
        gpio.F5 =1;
        delay_ms(500);
        gpio.F5 = 0;
        delay_ms(500);
        }

     if (gpio.gp4 == 0)              // while GP4 = switch pressed
        {
        gpio.F2 =1;
        gpio.F5 =1;
        delay_ms(500);
        gpio.F2 = 0;
        gpio.F5 =0;
        delay_ms(500);
        }
     }
       }

        }