Need help to create webmethod.

Hi all,

            Pls help me to create this webservice in asp.net and C#.net. Suppose I have table in back end called patient master which  hold the information about the patient. Fileds having like patientid, firstname, lastname, age, gender, contact no etc. patient id is alpha numeric auto increment values. So I want to create a dynamic web service which will have inserpatient, getpatient, update patient, and delete patient method. These web method will be used in many places of asp.net page. And while inserting new patient we have to consider the last patient id and the new entry will be last one. Pls somebody help me how can I implement these method with sample in C#.net. Pls help me……