Disable back and next button of web Browser

I Like to disable back Button if i kill the session please send the code

call the javascript function ie call the javascript function from the body tag hope this solves u r problem function disableBack() { nextPage = new String(history.forward()); if (nextPage == "undefined") { //this has been done thru submit button or a hyperlink } else { location.rel='nofollow' href = window.history.forward(); // when the back button or the backspace is hit } }