hello all ; can any one hellp me i write aprogram . when i put it like below it can be compiled but if i put delay_time after timer0 interrupt it can not be compiled void delay_time (unsigned int time_end) { unsigned int index; for (index = 0; index < time_end; index++); } void timer0 (void) interrupt 1 { static unsigned char idata var1=0; static unsigned char idata var2=0; if(++var1==255) { var1=0; if(++var2==13) { var2=0; read_from_8046(); } } TF0=0; EA=1; } thanks all;