Hello! I heve 241 point, an i want to get te first and the last point,and i name them i@end =1

if i maualy enter total number, i get this:

if(@ptnum == 240){
i@end = 1;
}
if(@ptnum == 0){
i@end = 1;
}
and it is working, but if i want to make it change prociduraly:
if(@ptnum == npoints(0)){
i@end = 1;
}
if(@ptnum == 0){
i@end = 1;
}

i don't get the right result

npoints(0) returns 241

Soothsayer
npoints(0) returns 241

the time i sent it i realizet that i have to put -1 in this function)
Thank you!