Actually i struct at one place in my coding, i need your help in that. Actually, i made two button on one jsp page for ON and OFF. And two other programs for ON and OFF. So, whenever user hit On button, servlet program for ON will run and switch ON the device attached to that sensor. But when i am hitting the other button i.e OFF it doesnt work. And if we restart the apache server then it starts working. Means, to make other button workable i have to restart the apache server, which should not happen, both button should work without restarting the server. I dont know what to do. Can any one help me , what to do to solve this problem.