If it is something like monkey said then couldn't you do this:
1) Create a varible called distance and its value could be 500
2) As the object moves, you could subtract from distance every game loop
3) Call a If statement= if ((distance < 50) && (distance >30)){
Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, //code here}
4) Call another If statement for strike= if (distance < 30) {
//code here}
Not sure if something like that would work, but you could try something like it.
1) Create a varible called distance and its value could be 500
2) As the object moves, you could subtract from distance every game loop
3) Call a If statement= if ((distance < 50) && (distance >30)){
Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, Ã, //code here}
4) Call another If statement for strike= if (distance < 30) {
//code here}
Not sure if something like that would work, but you could try something like it.