1 SHOPPING TROLLEY HANDLE WITH RFID TAG TECHNICAL FIELD The present invention relates to a handle for a shopping trolley, and more particularly to a handle 5 for use with a radio-frequency identification (RFID) tag. BACKGROUND Supermarkets and other retailers provide shopping trolleys (or carts) to allow customers to carry and purchase goods, and transport these goods between the store and their vehicle typically in a car-park associated with the store and/or a shopping centre. One of the problems faced by such 10 supermarkets and other retailers is the removal of such shopping trolleys from the shopping centre and car-park, as some customers use the trolleys to take purchased goods home, whilst others including youths and children will remove trolleys for joyrides and other purposes. In many instances shopping trolleys removed from shopping centres and their associated car parks puts a large cost impost on retailers and the local councils, as shopping trolleys are commonly abandoned 15 in the street, and must be searched for, collected and returned. Furthermore shopping trolleys removed from shopping centres and their associated car parks, generally require greater maintenance and repair, as such trolleys are not intended for street use and they are sometimes vandalized. Various attempts have been made to minimize the removal of shopping trolleys from a retail 20 environment. For example, some retailers lock the shopping trolleys together, and employ a coin release mechanism, which requires a shopping trolley to be returned to a trolley bay in order to have the coin refunded. Another attempt has been to individually identify and track the shopping trolleys. One such arrangement is disclosed in International Publication No. W02006/087070 (All4Retail SA) where 25 a shopping trolley has an RFID tag with transponder fastened externally of the shopping trolley handle. The RFID tag and transponder is in a "belt form" and wrapped around the tubular handle of ref: P24163AU01 081113 2 the shopping trolley and secured thereto. Whilst this arrangement allows for existing shopping trolleys to have RFID tags fitted thereto, a disadvantage of this arrangement is that the RFID tag can easily be damaged, tampered with and/or removed. The present invention seeks to ameliorate over the prior art, by allowing an RFID tag to be fitted to 5 a shopping trolley in a manner that minimizes the risk of damage, tampering and removal of the RFID tag. SUMMARY OF INVENTION In a first aspect the present invention consists in a handle for a shopping trolley, said handle includes a plastic tubular member having a plurality of integrally formed elongate ribs extending 10 axially along the internal bore thereof, said ribs are used to secure and support an RFID tag within said tubular member. Preferably said RFID tag includes a housing having a plurality of integrally formed elongate grooves extending axially along the outer surface thereof, and in order to secure and support said RFID tag within said tubular member, each of said plurality of grooves slidably engages with one 15 of said plurality of ribs. Preferably said plurality of elongate ribs is at least three elongate ribs equidistantly spaced about the internal bore of said tubular member, and said plurality of grooves is at least three grooves equidistantly spaced about said housing. Preferably an RFID chip and associated power source is housed within said housing. 20 In a second aspect the present invention consists in a shopping trolley handle and RFID tag in combination, said handle includes a plastic tubular member having a plurality of integrally formed elongate ribs extending axially along the internal bore thereof, said RFID tag including an RFID chip and associated power source housed within a housing, and said ribs engaging a plurality of axially extending grooves integrally formed on the outer surface of said housing in order to secure 25 and support said RFID tag within said tubular member. ref: P24163AU01 081113 3 BRIEF DESCRIPTION OF DRAWINGS Fig. 1 depicts a side view of a handle for a shopping trolley in accordance with a first embodiment of the present invention. Fig. 2 depicts a front view of the handle shown in Fig. 1. 5 Fig. 3 depicts a side view of an RFID tag for use with handle shown in Fig. 1. Fig. 4 depicts a front view of the RFID tag shown in Fig. 3. Fig. 5 depicts an internal schematic of the RFID tag shown in Fig. 3. Fig. 6 depicts a schematic side view of the RFID tag shown in Fig. 3 slidably engaged within the handle of Fig. 1. 10 Fig. 7 depicts a schematic front view of the RFID slidably engaged within the handle as shown in Fig. 6. BRIEF DESCRIPTION OF PREFERRED EMBODIMENT Figs. 1 to 7 depict a shopping trolley handle 1 and an RFID tag 5 in a preferred embodiment of the 15 present invention. Handle 1 is a hollow tubular member made preferably of a plastic such as polycarbonate. Handle 1 is intended to be fitted to the rear of shopping trolley (not shown) and used in a conventional way by a user (not shown) to push and steer the shopping trolley. Handle 1 also acts as a holder to secure and support RFID tag 5 within its hollow space. As handle 1 is made of polycarbonate material it does not interfere with RFID signal as would occur with a 20 steel handle. Handle 1 has four axially extending elongate ribs 2 integrally formed along the internal bore 3 thereof. Ribs 2, best seen in Fig. 2, provide strength and rigidity to the polycarbonate material. Ribs 2 are equidistantly spaced about the internal bore 3. Whilst the size of handle 1 can vary due to different sizes of shopping trolleys, a typical size for a ref: P24163AU01 081113 4 tubular member of handle 1 when used with a typical supermarket shopping trolley would preferably be about 25.5mm external diameter with a wall thickness of about 1.5mm. Ribs 2 would preferably be semicircular and have a radius of 1.5mm. RFID tag 5 includes a housing 6 made of plastic, an RFID chip (circuitry) 7 and power source 8 5 which in this embodiment is shown as two AA batteries, see Fig. 5. The external surface 4 of housing 6 is provided with four axially extending semi-circular grooves 9 integrally formed therein. The size of housing 6 and the size and orientation of grooves 9, is such that RFID tag 5 may be slidably inserted into the bore (hollow space) 3 of handle (tubular member) 1 with grooves 9 engaging ribs 2 so that handle 1 securely supports RFID tag 5 in a fixed orientation relative to 10 handle 1. As such ribs 2 not only provide rigidity and strength to handle 1, but also the dual purpose of securing and supporting RFID tag 5 inside handle 1. It should be understood that a further tubular sleeve (not shown) of plastic material could be slidably fitted to handle 1. The sleeve may have indicia markings thereon, or possibly made of 15 transparent plastic with indicia bearing annular sheet media is disposed between the handle (tubular member) 1 and the sleeve. Handle 1 (with or without a sleeve) would be attached to the shopping trolley (not shown) by end caps (not shown) on the trolley. The combination of handle 1 and RFID tag 5 can be incorporated in presently designed shopping 20 trolleys, by substituting the existing handle with handle 1 and RFID tag 5 fitted thereto. Furthermore, existing shopping trolleys could be retrofitted with the present invention by removing the conventional handle, and then handle 1 and RFID tag 5 fitted thereto. One of the advantages of the present invention is that RFID tag 5 is hidden from view, and therefore it is less likely to be damaged, tampered or removed when compared to the RFID tag 25 shown in the prior art International Publication No. W02006/087070. Whilst the present embodiment depicts four ribs 2 engaging with four respective grooves 9, it ref: P24163AU01 081113 5 should be understood that the invention in another embodiment may have a different number of ribs and grooves, for example three ribs and three grooves could be employed without departing from the spirit and scope of the invention. In such embodiment the three elongate ribs would preferably be equidistantly spaced about the internal bore of said tubular member, and the three 5 grooves would preferably be equidistantly spaced about the housing. The terms "comprising" and "including" (and their grammatical variations) as used herein are used in an inclusive sense and not in the exclusive sense of "consisting only of'. ref: P24163AU01 081113