OPD Example

#include <a_samp>
#include <OPD> //OPD.inc

public OnPlayerHealthChange(playerid, Float:oldHealth, Float:newHealth, Float:oldArmor, Float:newArmor)
{
    new str[100];
    format(str, 100, "You just lost %.1f health and/or %.1f armor!", oldHealth - newHealth, oldArmor - newArmor);
    GameTextForPlayer(playerid, str, 3000, 3);
    return 1;
}