</head> <body> <p>判断百度的LOGO是否存在:<br> <IMG src="https://www.baidu.com/img/baidu_logo.gif" onerror="javascript:this.src='/images/logo.jpg'"></p> <p>如果不存在,则替换成本地网站logo:<br><IMG src="https://www.baidu.com/img/baidu_logo11.gif" onerror="javascript:this.src='/images/logo.gif'"></p> </body> </html> </head> <body> <p>判断百度的LOGO是否存在:<br>