I tried all the things out but cudnt solve hte problem of rebooting,but the reason i wanted to reboot the system was
that if someone wants to change the ip of the board,on runtime he had to reboot(as per my perception),
but now i have done that without needing to reboot.
the person can change the ip of the system,thru GUI and the changes are applied on runtime(though the link to the board is broken once) thru a series of ifconfig add del commands
still i wonder is there ny way thru wich teh system can be rebooted,if in future i have no option bt to reboot it
thanx a lot for ur replies