console
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8"/>
<title>select触发链接</title>
</head>
<body style="margin: 0">
<table style="background: DarkGray;width: 100%;height: 890px;">
<tr style="background: Cornsilk">
<td colspan="3" style="height: 10%;text-align:center;margin:50px 0; font:normal 56px/56px 'MicroSoft YaHei'">标 题</td>
</tr>
<tr>
<td style="background: Cornsilk; width:12%; text-align:center;margin:50px 0; font:normal 24px/24px 'MicroSoft YaHei';color:#ffffff">
<form action="" >
<select name='test' onchange="document.querySelector('#main').src=this.value">
<option value='https://baidu.com'>百度</option>
<option value='https://qq.com'>QQ</option>
<option value='https://ele.me'>饿了么</option>
</select>
</form>
</td>
<td colspan="2">
<iframe
src="https://baidu.com"; width="100%" id="main" height="100%" name="test"
></iframe>
</td>
</tr>
<tr style="background: Cornsilk"><td colspan="3" style="height: 2%"></td>
</tr>
</table>
</body>
</html>