This week's book giveaways are in the iOS and Features new in Java 8 forums. We're giving away four copies each of Barcodes with iOS: Bringing together the digital and physical worlds and Core Java for the Impatient and have the authors on-line! See this thread and this one for details.
I am guessing that Arun wants to run two different versions of Java (e.g. Java 1.4.2 and Java 5). This would be done by setting the PATH variable suitably, or by hard-coding the path to the java.exe file.