int main(void)
{

   DDRC = 0xFF; //output led
   PORTD = 0x04; //PD2 high for switch interrupt
   serial_Init();
   GICR = (1<<INT0);
   sei();
   while(1)
    {

     }
}
ISR (INT0_vect)
{

   serial_Tx("ATD<number>;rn");
}

ISR(USART_RXC_vect)
{


}

void serial_Tx(char *str)
{
for (unsigned int i=0;str[i]!=0;i++)
{
    UDR=str[i];
    while(!(UCSRA&(1<<UDRE)));
}
}

char serial_Rx()
{
while(!(UCSRA & (1<<RXC)));
return UDR;
}