Java Programming

Error :java is not recognised as an internal or external command,operable program or batch file/The System cannot find the path specified

My source code is as follows

/**
* The HelloWorldApp Class implements an application that
* Simply prints "Hello World!" to standard output
*/
Class HelloWorldApp {
public static void main(String[] args) {
System.out.println("Hello World!"); // Display the String
}
}

The above source code is saved in notepad in the file name txt field "HelloWorldApp.java". In the Command Prompt, while C:\>java\ Enter -> Error -->java is not recognised as ---------external command
------- operable program or batch file.
Again i modified command --->C:\>jdk6\bin\javac HelloWorldApp.java -->
Enter -->Error -->The system cannot find the path specified.
Following jdk files i installed
1Type of file :Application
Description: java[TM] platform SE binary size-376KB
jdk - 6u4 - windows - i586 - p - iftw.exe
2. Type Application
Description: Set up Launcher
Size 38.8MB
Location : C:\ Documents and Settings\ Arindam Biswas\Dekt\--
Could anyone please help me? Instead of picking up stones from
the vast sea, i shall be pleased if anybody pin points the problems.
If requires i am ready to talk through phone or mail.
damp(biswas.id.com)