代码如下：
<SCRIPT LANGUAGE="JavaScript"> <!-- Begin var checkflag = "false"; function check(field) { if (checkflag == "false") { for (i = 0; i < field.length; i++) { field[i].checked = true;} checkflag = "true"; return "Uncheck All"; } else { for (i = 0; i < field.length; i++) { field[i].checked = false; } checkflag = "false"; return "Check All"; } } // End --> </script> <form name=myform action="" method=post> <table width="133"> <tr><td width="125"> <b>软件系数调查：<br> </b> <br> <input type=checkbox name=list value="1">软件的界面<br> <input type=checkbox name=list value="2">特效很多<br> <input type=checkbox name=list value="3">分类详细<br> <input type=checkbox name=list value="4">完全免费<br> <input type=checkbox name=list value="5">特效很实用<br> <input type=checkbox name=list value="6">更新速度快<br> <br> <input type=button value=" 全部选定 " onClick="this.value=check(this.form.list)"> </td></tr> </table> </form>