IE FF Chrome浏览器离开弹窗揭示

IE FF Chrome浏览器离开弹窗提示

//--------------离开提示---------------------window.onbeforeunload = function(e){if(window.navigator.userAgent.indexOf("Chrome") !== -1 ){return '提示!';}if ( e && e.preventDefault ){e.preventDefault();}else{        window.event.returnValue = '';}}