t=marker.key (1).time

grav=[0,30]

vel=position.velocity_at_time(t)

A=position.value_at_time(t)

while(t<time){

t=t+this_comp.frame_duration,

A= A+vel*this_comp.frame_duration,

vel= vel+grav;

if(A[1]>this_comp.height-this_layer.height/2) {vel[1]=-vel[1]*.6}

if(A[1]<this_layer.height/2) {vel[1]=-vel[1]}

if(A[0]>this_comp.width-this_layer.width/2) {vel[0]=-vel[0]}

if(A[0]< this_layer.width/2) {vel[0]=-vel[0]}

}

if(time < marker.key (1).time){A=position}

A