//if its not 0, the engine will pass it, and fly right through to next if / code
if (car_car==0)//while the variable is 0, you can set up these keys to work
{
if(key_z)
{
//you code, when you click z
}
if(key_a)
{
//you code, when you click a
}
if(key_d)
{
//you code, when you click d
}
if(key_s)
{
//you code, when you click s
}
}
