arun shivanna

I would like run only one instance of my program.
if one instance is running, i should get a message it is already running.
now if i can run 'n' number of instances.
like "i have QsFrame class which is main class"
if i run "java QsFrame" then until i exit from this frame i should run another instance.

I have table in excel Sheet how to read from this xls file. please reply urgent