1. A police-emergency system communication comprising:

a magnetic card composed of an identification device, a battery device, a sound-light device, a control circuit, a wireless communication module wherein said control circuit comprising an emergency button and a confirm button; said magnetic card which utilizes the control circuit to generate a signal;

a host server comprising a wireless communication module, a system, a database and a microprocessor; said host server which receives the signal from the magnetic card and judges the source of the signal; and

a police-emergency system of police-citizen connection receiving the signal from said host server and connecting with the policemen immediately for the police to go on the scene in time;

thereof said identification device of said magnetic card used as an identification of the user, when there the emergency events happened, the user pressing-down the emergency button and the confirm button concurrently to generate a signal and the signal which will be transmitted onto the host server through the wireless communication module;

the wireless communication module of said server receiving the signal coming from the magnetic card and transmitting the signal onto the microprocessor; said processor comparing the data in the database to judge whether the signal source in conformity with the data in the database; if yes, said signal transmitted by said host server onto the police immediately for the policemen arrive on the scene where crimes happened.

2. The police-emergency system as mentioned in claim 1, wherein the identification device of said magnetic card achieves the I.D. identification through the way of bar-code reading by the bar-code scanner.

3. The police-emergency system as mentioned in claim 1, wherein the identification device of said magnetic card achieves the I.D. identification through the way of bar-code reading by the bar-code scanner which is an electronic bar.

4. The police-emergency system as mentioned in claim 1, wherein the identification device of said magnetic card achieves the I.D. identification through the way of bar-code reading by the bar-code scanner of which the card is an integrated circuit (IC) card.

5. The police-emergency system as mentioned in claim 1, wherein the transmitting way is radio frequency (RF) transmittance for the wireless communication module of the magnetic card and the host server.

6. The police-emergency system as mentioned in claim 1, wherein the transmitting way is BLUETOOTH transmittance for the wireless communication module of the magnetic card and the host server.

7. The police-emergency system as mentioned in claim 1, wherein the control circuit of said magnetic card comprises an emergency button and a confirm button, wherein said emergency button and confirm button is a press device which is used to trigger a signal to the control circuit and transmits the signal to the host server through the control circuit.

8. The police-emergency system as mentioned in claim 1, wherein the control circuit of said magnetic card comprises an emergency button and a confirm button, wherein said emergency button and confirm button is a thin-film device which is used to trigger a signal to the control circuit and transmits the signal to the host server through the control circuit.

9. The police-emergency system as mentioned in claim 1, wherein the sound-light device of said magnetic card is LED which is used to show the condition of battery power.

10. The police-emergency system as mentioned in claim 1, wherein the sound-light device of said magnetic card is a bee-sounder which is used to make noise and remind the condition of battery power.

11. The police-emergency system as mentioned in claim 1, wherein the system of the host server utilizes the microprocessor to catch the data inside the database and transmits the signal onto the magnetic card through the wireless communication module, the control circuit of said magnetic card will generate a response signal automatically, said signal is transmitted to the host server through the wireless communication module, the microprocessor of said host server compares the signal with the data in the database and transmit the data to the absentee system to manage the absentee condition of the staffs.