无法弹出alert,请帮忙看下是怎么回事,自己怎么也找不到问题点,谢谢了
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | <!DOCTYPE html> <html> <head> <meta charset= "UTF-8" > <title>跨浏览器事件处理</title> <script type= "text/javascript" > var eventUtil = { // 添加句柄 addHandler: function (element,type,handler){ if (element.addEventListener){ element.addEventListener(type,handler, false ); } else if (element.attachEvent){ element.attachEvent( 'on' +type,handler); } else { element[ 'on' +type]=handler; } }, // 删除句柄 removeHandler: function (element,type,handler){ if (element.removeEventListener){ element.removeEventListener(type,handler, false ); } else if (element.detachEvent){ element.detachEvent( 'on' +type,handler); } else { element[ 'on' +type]= null ; } } } function showMes(){ alert( "跨浏览器的click事件" ); } var btn5=document.getElementById( "btn" ); eventUtil.addHandler(btn, 'click' ,showMes); </script> </head> <body> <div> <input type= "button" id= "btn" value= "按钮" > </div> </body> </html> |