RegisterHam(Ham_TakeDamage, "player", "fw_TakeDamage")

public fw_TakeDamage(victim, inflictor, attacker, Float:damage, damage_type)
{
 // Non-player damage or self damage
 if (victim == attacker || !is_user_connected(attacker))
  return HAM_IGNORED;
 
  if (damage_type & (1<<24))
  {
   ......
  }
}