Problems with signal functions

For the first time in many years I need to simulate I/O by using a signal function - specifically - toggle the T0 pin (P1.2 on a LPC915) as I am using Timer 0 as a counter. I have two problems, best described by a segment of code stripped down to try to find the fault.

SIGNAL void toggle_T0 (void)
{
while(1)
    {
    PORT1 |= 0x04;
    twatch (0.2);
    PORT1 &= ~0x04
    twatch (0.2);
    }
}

void main (void)
{
} 

Even with this "nothing program" I get : error C129: missing ';' before 'void' with a line number that points to the signal declaration. Also, what is the correct name for the VTREG that defines the pins of Port 1?