[Konstantinos]

You cannot use both break and return one after another.

PHP код:

GetIDbyVDID(vehicleid)
{
    for(new i = 0, j = GetPlayerPoolSize(); i <= j; i++)
    {
        if (PlayerInfo[i][pDatabaseID] == VehicleInfo[vehicleid][carOwner])
        {
            printf("Returning %d", i);
            return i;
        }
    }
    return INVALID_PLAYER_ID;
} 


What do you reset "CarOwner" to so we won't have to loop through players when a vehicle is not owned by anyone?

Be it 0, INVALID_PLAYER_ID or whatever, add it at the top of the function.

pawn Код:

if (VehicleInfo[vehicleid][carOwner] == /* RESET VALUE/NO OWNER */) return INVALID_PLAYER_ID;

and then usage:

pawn Код:

new p_id = GetIDbyVDID(vehicleid);
if (p_id != INVALID_PLAYER_ID) // necessary if you want to use "p_id" in arrays.
{
    // messages or what you want..
}