function getVelocity(index)
{
players = Entity.GetPlayers();
for (i=0; i < players.length; i++);
{
var velocity = Entity.GetProp( index, "CBasePlayer", "m_vecVelocity[0]" );
var speed = Math.sqrt( velocity[0] * velocity[0] + velocity[1] * velocity[1] );
}
return speed;
// Pass entity index, get velocity in return.
}