hydraulic pressure would bea good thing as ping pong ball is lighter than water.If we will use air pressure,chances of leakage will be more resulting in loss of pressure force.

Selection Process

Selection is the process of choosing from a group of applicants those individuals best suited for a particular
position. Most managers recognize that employee selection is one of their most difficult, and most important,
business decisions. This process involves making a judgment -not about the applicant, but about the fit
between the applicant and the job by considering knowledge,skills and abilities and other characteristics required to perform the job Selection procedures are not carried out through standard pattern and steps in this. Process can vary from organization to organization some steps performed and considered important by one organization can be skipped by other organization.
Environmental Factors Affecting the Selection Process A permanent, standardized screening process could greatly simplify the selection process. However, development of such a process even if it were possible and desirable would not eliminate deviations to meet the unique needs of  particular situation.

Legal Considerations
Legislation, executive orders, and court decisions have a major impact on human resource management. It is important for hiring managers to see the relationship between useful and legally defensible selection tools.

Speed of Decision Making
The time available to make the selection decision can have a major effect on the selection process. Closely following selection policies and procedures can provide greater protection against legal problems; however, there are times when the pressure of business will dictate that exceptions be made.

Organizational Hierarchy
Different approaches to selection are generally taken for filling positions at different levels in the organization.

Applicant Pool
The number of applicants for a particular job can also affect the selection process. The process can be truly
selective only if there are several qualified applicants for a particular position. The number of people hired for a particular job compared to the individuals in the applicant pool is often expressed as a selection ratio.

Type of Organization
The sector of the economy in which individuals are to be employed private,  governmental, or not-forprofit can also affect the selection process.

Probationary Period
Many firms use a probationary period that permits evaluating an employee's ability based on performance. This may be either a substitute for certain phases of the selection process or a check on the validity of the process.

Selection Criteria
Mostly the selection of applicant depends upon the
following factors or criterions.
1. EDUCATION
2. COMPETENCIES
3. EXPERIENCE
4. SKILLS AND ABILITIES
5. PERSONAL CHARACTERISTICS

Applicant who is best fit should be hired instead of hiring a person with extra ordinary skills it means right person for right job should be hired person who is over or under qualified for the particular job will not be able to adjust in the organization.

STEPS IN THE SELECTION PROCESS
The selection process typically begins with the preliminary interview; next, candidates complete the application for employment. They progress through a series of selection tests, the employment interview, and reference and background checks. The successful applicant receives a company physical examination and is employed if the results are satisfactory. Several external and internal factors impact the selection process, and the manager must take them into account in making selection decisions. Typically selection process consists of the following steps but it is not necessary that all organization go through all these steps as per requirement of the organization some steps can be skipped while performing the selection process.
1. Initial Screening
2. Application Blank
3. Pre-employment Testing
. General Intelligence Tests
. Aptitude Tests
. Personality and Interest Tests
. Achievement Tests
. Honesty Tests
4. Interview
. Structured Interview
. Unstructured Interview
. Mixed Interview
5. Background Checks
6. Conditional job offer
7. Medical Exam/Drug Tests
8. Final Selection Decision

In n-tier architecture the entire application is divided in several pieces. These pieces can be logical or physical. Each piece performs a specific task such as displaying user interface or data access. There can be any number of tiers or layers of such pieces. Hence, the name n-tier (Note that many times the terms tier and layer are used interchangeably). However, most commonly applications have 3 distinct tiers or layers. They are:

• Presentation Layer
• Business Logic Layer
• Data Access Layer

As you can guess, presentation layer is nothing but a piece of software that deals with user interface of your application. Displaying data to the end user and allow them to interface with it is the core functionality of this layer.

In most of the cases the data entered by the end user needs some kind of validation or further processing. This is the responsibility of Business Logic Layer.

Finally, your application data needs to be stored and retrieved in some data store (RDBMS, XML etc.). This task is handled by Data Access Layer.

In short, the process works like this:

• User requests for some application data.
• The data access layer retrieves the data and is forwarded to the presentation layer via business logic layer. Sometimes data access layer gives this data directly to presentation layer.
• Presentation layer receives the data to be displayed via business logic layer.
• The user changes the data and initiates the appropriate action (such as insert, or update).
• The business logic layer validates the data submitted by the user.
• If the data is valid it is handed over to data access layer for updating into the database.

Advantages of N-Tier ArchitectureAt first glance this division of tasks may seem to be unnecessary. However, it gives following benefits:

• The applications gets divided in logically isolated pieces reducing tight coupling between the UI, business processes and database.
• Change in the underlying database and data access methods do not have any effect on the presentation layer or client application.
• Client application no longer has SQL statements embedded in it. This makes it de-coupled from rest of the application.
• Table and column names can be effectively eliminated from the client-side code.
• The client application is unaware from where data comes (location transparency).
• It becomes easier to modify or extend your application, without breaking or recompiling the client-side code.

The downside of n-tier architecture is that you need to create many isolated classes and pieces of software. However, benefits of n-tier applications will far outweigh its disadvantage.

System.Globalization and System.Resources.