Change the size of a dropdown list (ComboBox)
<html> <head> <script type="text/javascript"> function formAction(){ var x=document.getElementById("mySelect") x.size="3" } </script> </head> <body> <form> <select id="mySelect"> <option>1</option> <option>2</option> <option>3</option> <option>4</option> </select> <input type="button" onclick="formAction()" value="Change size of list"> </form> </body> </html>