how to insert, retrieve data from,to db(code)....

Hi, i have created login page n in that a registration form also in jsp, my doubt is-when new user register his details,(for ex,username,password,dob,gender) 1.how that data will b stored in db(m using sybase). 2.also hw to retrieve the data from db. cn u plz tel me the code in detail.n i thk it shud b written in jdbc.....i ve written sum code,bt gting so many doubts in that....so plzzzz help me by giving some code with sum example.....

3.and i thk i ve to write sum validations for username, password using javascript,hw to write that,n in wch pgm i ve to write(i mean, in login jsp pgm itself r in new jsp pgm) if it is in login pgm whr it shud b coded(before username,pasword fields code r after that..... 4.n still wt r d various validations that shud b done for registration form, for wch fieds.....(giv code for every field plz.....) plzzzzzz giv code for all queries ........so that i cn understd perfectly.