|   | Auto Download of the Java Platform | 
The Windows releases of Java Plug-in and Java Web Start make 
  use of the codebase attribute of the OBJECT element 
  to autodownload and install a particular version of the JRE. See:
By specifying a particular .cab file in the codebase, 
  a particular version of the JRE can be automatically downloaded and installed 
  as required by an applet or application. For a list of the available .cab 
  files, see Autodownload Files. Note that not 
  every release of the JRE has an associated .cab file for autodownload.
For additional information read the technical article on Auto Install.