[viskor]

AttachObjectToPlayer(objectid, playerid, Float:OffsetX, Float:OffsetY, Float:OffsetZ, Float:rX, Float:rY, Float:rZ)

is true

you use:
AttachObjectToPlayer(playerid,objectid , Float:OffsetX, Float:OffsetY, Float:OffsetZ, Float:rX, Float:rY, Float:rZ)

you tell that the player is attach to the objet you ^^

you need change the name of objet for the playerid, and the playerid for the name