polling or interrupt for 3 stages timer/alarm with pic , advise needed

[deepmak]

Good day all,
im fairly new to micro controllers and their programming , i want to design a device that can consist of a main board connected to push button(s) (one or two in series ) , with 4 outputs for warning devices and it would be used to confirm an operator attendance in their room ,and it would operates like this :
the supervisor sets a certain period , basically 3 minutes ( or 6 or 12 ) , the operator should push the button at their desk once before the period elapse to confirm they are at their desk , should the delay pass , a visual warning will operate , pressing the button will reset the delay and the count start over
if say 15 second passed with no operator interaction , a sound warning start in the operator room , again pressing the button will reset the delay and start over.
if no interaction again , a second stage sound warning will sound at the supervisor room , having them to check the room and push the button to silent all warnings and start over
if no interaction still after the second stage alarm , a third stage sound warning will start after say 90 seconds at the staff room or other place where worker would be , and it will sound until the warning are silenced from the operator room.
i thought of attaching the push button as external interrupt to reset all warning and start the delay over , however all books or lectures i read about interrupt were mentioning that interrupt will resume the flow of the program after being served , meanwhile i need to reset the delay with every push/press.
sorry for being lengthy but is it ok for interrupts to change the flow of execution ? like having a "GOTO Start1 " statement to direct the control to the start of program ?
on the other hand , i thought of the following code with polling , could you please check it ?

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Code C - [expand]
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void main() {
int i,j,h,k;
trisa=0;
trisb=1;
porta=0;
while (1) {
start1: for (i=1;i<=3600;i++) {
delay_ms(50);
if (portb.f0==0) // button pressed
i=1;}
porta.f0=1; // first stage visual warning
for(j=1;j<=300;j++) {
delay_ms(50);
if(portb.f0==0) {
porta.f0=0;
goto start1;}}
porta.f1=1; // first stage sound warning
for(h=1;h<=300;h++) {
delay_ms(50);
if (portb.f0==0){
porta.f0=0;
porta.f1=0;
goto start1;}}
porta.f2=1; // second stage sound warning
for (k=1;k<=1800;k++) {
delay_ms(50);
if (portb.f0==0) {
porta.f0=0;
porta.f1=0;
porta.f2=0;
goto start1;}}
porta.f3=1; // thrid stage sound warning
while (1){
if(portb.f0==0){
porta.f0=0;
porta.f1=0;
porta.f2=0;
porta.f3=0;
goto start1;}}
}
}

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Thanks in advance , i plan to add delay configuration later if this works
Edit : syntax corrected after coding in Mikroc IDE , sorry for errors (wrote code from work using notepad)
simulation works using PIC16F84A
Regards