AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Innovation Patent Applicant(s): Well-In Production Company Limited Invention Title: Portable closet with a heater The following statement is a full description of this invention, including the best method for performing it known to me/us: - 2 PORTABLE CLOSET WITH A HEATER CROSS-REFERENCE TO RELATED APPLICATIONS The application claims the priority benefits of Hong Kong Short-Term Patent Application No.10106379.6 filed on June 5 30, 2010, the contents of which are hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The present invention relates to the field of a portable closet with a heater. 10 BACKGROUND OF THE INVENTION Closets are usually constructed fixedly, and there are few closets in suburbs. Thus, it would be inconvenient for outdoor activities, especially for the elders and children. Although there are some kinds of portable 15 closets available for children, such kinds of closets need cleaning with water, and it would be inconvenient for the use of such closets without supply of water. SUMMARY OF THE INVENTION The object of the present invention is to provide a 20 portable closet which does not need cleaning immediately after use. The portable closet with a heater may comprise: a tub composed of a bottom sheet and a plurality of side sheets and forming a cavity for receiving urine and excrement of 25 users, in which adjacent two side sheets engage with each other in a manner of a concave-convex structure, while the bottom sheet is provided with grooves at edges thereof, and each side sheet is inserted into a groove to be fixed to the bottom sheet; a cover detachably covering the tub, 30 in which the cover includes a toilet seat and a lid, the toilet seat is provided with an aperture for the excrement 2621764_1 (GHMatters) P86783.AU 29/03/11 -3 and urine entering into the tub, and the lid is pivotably connected to the toilet seat beside the aperture, for selectively opening the aperture, and at least two hooks are provided on a lower surface of the toilet seat around 5 the aperture; a receiving bag hung from the hooks within the cavity for receiving the urine and excrement, in which a sponge and activated carbon are placed; a plastic bag covering the receiving bag; a supporting base provided within the tub for supporting the receiving bag and the 10 plastic bag; a rod provided within the tub and not interfering with the supporting base, which is used for supporting toilet tissues; a slit formed through the toilet seat and aligning with the rob to enable the toilet tissues to pass through; a heater provided in the toilet 15 seat for heating the toilet seat when the heater is turned on. The heater may be provided in the lower surface of the toilet seat, and is composed of an aluminum sheet covered with rubber, a ceramic heater film, a temperature sensor, 20 a circuit and a battery consequently. The supporting base may be divided into three compartments vertically, in which an upper compartment is used to support the receiving bag and the plastic bag; a middle compartment is used to contain spare receiving bags and 25 plastic bags; and a lower compartment is used to contain a charger and/or a USB cable. A display connected to the heater is provided at a side of the toilet seat, and a charging port through which the battery of the heater is charged is provided at a side of 30 the toilet seat. The charging port is a common socket, a USB port or a combination of the formers, by virtue of which the battery of heater is charged. 2621764_1 (GHMatters) P867B3.AU 29/03/11 - 4 The present portable closet with a heater is convenient for use, and does not need cleaning with water immediately after use by using receiving bags and sponges. The receiving bags and sponges could be dropped to a suitable 5 place after being used. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in detail with reference to the accompanying drawings, in which, Fig. 1 is a perspective schematic view of a portable 10 closet of the present invention; Fig. 2 is a cross-sectional view of the portable closet of the present invention; and Fig. 3 is a cross-sectional view of a cover of the present invention. 15 DETAILED DESCRIPTION OF THE INVENTION As shown in Fig. 1, the present portable closet with a heater comprises a tub 1, a cover 2 detachably covering the tub 1, a receiving bag 3 placed within the tub 1 for receiving excrement and urine of users. The receiving bag 20 3 could be disposable and be made of non-woven materials. The receiving bag 3 could be provided with a sponge 5 and activated carbon therein, in which the sponge 5 is used to absorb water in the excrement and urine, while the activated carbon is used for sterilization and 25 deodorization. As shown in Fig. 3, the cover 2 includes a toilet seat 21 and a lid 20. The toilet seat 21 is provided with an aperture for the excrement and urine entering into the tub 1. The lid 20 is pivotably connected to the toilet seat 21 30 beside the aperture, for selectively opening the aperture. At least two hooks 22 are provided on a lower surface of the toilet seat 21 around the aperture, for hanging the 2621764_1 (GHMatters) P86783.AU 29/03/11 -5 receiving bag 3. Between the lid 20 and toilet seat 21, a fastener 23 is provided for fastening the lid 20 with respect to the toilet seat 21. The cover 2 is made of thermal conductive materials, and is provided with a 5 heater 4 in its lower surface. The heater 4 is composed of an aluminum sheet covered with rubber, a ceramic heater film, a temperature sensor, a circuit and a battery consequently. The heater could heat the toilet seat 21 intermittently and work for 1 hour with the battery, to 10 enable to keep the temperature of the toilet seat 21 at a suitable level. A charging port 24 is provided at an edge of the toilet seat 21, through which the battery could be charged. The charging port 24 could be a universal serial bus (USB) port or a common socket or a combination of the 15 formers. Thus, the battery of the heater could be charged by means of a USB cable or a charger 17. Furthermore, a light emitting diode (LED) display 26 could be provided on an edge of the toilet seat 21 for displaying the status of the heater 4. 20 As shown in Fig. 2, the tub 1 is composed of a bottom sheet 10 and a plurality of side sheets 11, and thereby a cavity 12 for receiving excrement and urine could be formed within the tub 1. The bottom sheet and the side sheets could be made of plastics. Adjacent two side sheets 25 11 engage with each other in a manner of a concave-convex structure. In another word, a side edge of a side sheet is provided with several concave regions, while an adjacent side edge of the other sheet is provided with matching convex portions. The concave regions and the matching 30 convex portions engage with each other to enable the two adjacent side sheets attach to each other. The bottom sheet is provided with grooves at edges thereof, and each side sheet is inserted into a groove to be fixed to the bottom sheet. 35 The receiving bag 3 is hung from the hooks 22 within the cavity 12. A reusable plastic bag 15 could cover the 2621764_1 (GHMatters) P86783.AU 29/03/11 - 6 receiving bag 3, to avoid leakage and decrease an offensive odor. A supporting base 14 is provided within the tub 1 and could be made of corrugated paper. The supporting base 14 is divided into three compartments 5 vertically, in which an upper compartment is hard enough for supporting the receiving bag 3 and the plastic bag 15; a middle compartment is used to contain spare receiving bags and plastic bags, and each of the spare receiving bags could contain a sponge 5 and activated carbon therein 10 in advance; and a lower compartment is used to contain the charger 17 or USB cable by virtue of which the battery of the heater could be charged. The portable closet could further be provided with a rod 13, and a through hole 16 at matching locations in two 15 opposite side sheets 11 for supporting the rod 13. Each end of the rod 13 is provided with two washers. The washers are used to fix the end of the rod within the through hole from inside and outside of a side sheet. The rod 13 is located in the tub 1 near a side sheet, to not 20 interfere with the supporting base 14. The rob 13 is used to support toilet tissues 18. A slit 25 is formed through the toilet seat 21 aligning with the rob 13 to enable the toilet tissue 18 to pass through, as shown in Fig. 1. Before the present portable closet is used, the toilet 25 seat 21 is opened firstly, and a receiving bag 3 is hung from the hooks 22 and provided with a sponge 5 and activated carbon therein. Then, a plastic bag 15 is placed outside the receiving bag 3 and is also hung from the hooks. Subsequently, the toilet seat 21 is closed, and 30 thereby the plastic bag 15 and receiving bag 3 is contained within the cavity 12 and supported on the supporting base 14. A user could open the lid 20 to use the portable closet. After used, the receiving bag 3 could be taken out, sealed and placed to a suitable place for 35 collection. Then, a new receiving bag 3 could be placed in the plastic bag 15, to enable to be used next time. 2621764 1 (GHMatters) P86783.AU 29/03/11 - 7 In winter, users could turn on the heater 4 to warm up the toilet seat 21. Furthermore, a switch could be provided for the heater, and the heater could only works after being supplied with power. Therefore, it would be of 5 safety for the users. The heater 4 is flush with the toilet seat 21 to make it comfortable for the users to sit thereon. Although the description of the present invention is made with reference to the preferred embodiments, the present 10 invention is not limited to these embodiments. Various modifications and changes can be made to the invention by those skilled in the art without departing from the spirit and scopes of the present invention. In the claims which follow and in the preceding 15 description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but 20 not to preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the 25 common general knowledge in the art, in Australia or any other country. 2621764_1 (GHMatters) P86783.AU 29/03/11