<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>ドロップダウンリストやリストボックスの選択項目の操作</title> <link href="/gudon/css/default.css" rel="stylesheet" type="text/css" /> <script type="text/javascript"> var chgCnt = 0; function chgButton_onclick(select1) { var i = select1.selectedIndex; chgCnt++; select1.options[select1.selectedIndex] = new Option("changeText" + chgCnt, "changeValue" + chgCnt, false, true); } var insCnt = 0; function insButton_onclick(select1) { var j = select1.selectedIndex; select1.options.length++; for(var i = select1.options.length - 1; i > j; i--) { select1.options[i].text = select1.options[i - 1].text; select1.options[i].defaultSelected = select1.options[i - 1].defaultSelected; select1.options[i].selected = false; } insCnt++; select1.options[j] = new Option("insertText" + insCnt, "insertValue" + insCnt, false, true); } var addCnt = 0; function addButton_onclick(select1) { addCnt++; select1.add(new Option("addText" + addCnt, "addValue" + addCnt)); } function delButton_onclick(select1) { select1.options[select1.selectedIndex] = null; } function numButton_onclick(select1) { select1.options.length=4; } </script> </head> <body> <h1>ドロップダウンリストやリストボックスの選択項目の操作</h1> <hr /> <form action="test1.php"> <select name="select1"> <option value="value1">text1</option> <option value="value2">text2</option> <option value="value3">text3</option> </select><br /> <input name="chgButton" type="button" value="項目の修正" onclick="chgButton_onclick(this.form.select1);"/><br /> <input name="insButton" type="button" value="項目の挿入" onclick="insButton_onclick(this.form.select1);"/><br /> <input name="addButton" type="button" value="項目の追加" onclick="addButton_onclick(this.form.select1);"/><br /> <input name="delButton" type="button" value="項目の削除" onclick="delButton_onclick(this.form.select1);"/><br /> <input name="numButton" type="button" value="項目数の4に変更" onclick="numButton_onclick(this.form.select1);"/><br /> </form> </body> </html>