AE - Particels - emit with markers

p = 9999; //number of particles to emit
fo = 7; //falloff time for emitting particles (in frames)
//(*falloff values less than 2 don't seem to emit any particles*)

//////////////////////////////////////////////////

m = thisComp.marker;
inx = 1;
tf = framesToTime(fo);

t = m.nearestKey(time).time;
inx = m.nearestKey(time).index;
inx = (time > t )? inx : inx -1;

if ( inx < 1){
0
}else{
t = m.key(inx).time;
tf = t + tf;
linear ( time, t , tf, p, 0)
}