点击运行
<html> <head> <script type="text/javascript"> function changeSize() { document.getElementById("mySelect").size=4 } </script> </head> <body> <form> <select id="mySelect"> <option>苹果</option> <option>桃子</option> <option>香蕉</option> <option>桔子</option> </select> <input type="button" onclick="changeSize()" value="改变大小"> </form> </body> </html>
运行结果
