public boolean Validate(String username,String password) {
		boolean valid=false;
		try {
			Class.forName("org.sqlite.JDBC");
			java.sql.Connection conn = DriverManager.getConnection(sqllite_jdbc_path);
			Statement stat = conn.createStatement();
			ResultSet rs = stat.executeQuery("select count(*) as num from user_info where username='"+username+"' and password='"+password+"'");
			int result=0;
			while(rs.next()){
				result=rs.getInt("num");
			}
			rs.close();
			conn.close();
			if(result==1){
				valid=true;
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return valid;
	}