i have a box and i want when i press y key it move.i write this code but in game when i press y key a message appear and say : crash in newtonbodyaddforce

action mynewtonwehicle
{
my.skill1 = 30; //mass
my.skill2 = 0.1;
my.skill3 = 0.1;
my.skill4 = 0.1;
my.skill5 = 0.1;

my.flag2 = on;

NewtonWoodEntity();

var p;
p = NewtonGetBody (my);

while(1)
{
if(key_y )
{
NewtonBodyAddforce(p,vector(200,0,0));
}
wait(1);
}
}

and if i change to NewtonBodyAddforce(p,2000,0,0); nothing happend.