<!-- 要实现此效果需要 1 个步骤： -->
<!-- 第 1 步： -->
<!-- 把下面的代码加到<BODY></BODY>区域中： -->
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
function checkAll() {
for (var j = 1; j <= 9; j++) {
box = eval("document.checkboxform.C" + j);
if (box.checked == false) box.checked = true;
}
}
function uncheckAll() {
for (var j = 1; j <= 9; j++) {
box = eval("document.checkboxform.C" + j);
if (box.checked == true) box.checked = false;
}
}
function switchAll() {
for (var j = 1; j <= 9; j++) {
box = eval("document.checkboxform.C" + j);
box.checked = !box.checked;
}
}
// End -->
</script>
<form name=checkboxform>
<input type=checkbox name=C1 checked>C1<br>
<input type=checkbox name=C2 checked>C2<br>
<input type=checkbox name=C3 checked>C3<br>
<input type=checkbox name=C4 checked>C4<br>
<input type=checkbox name=C5 checked>C5<br>
<input type=checkbox name=C6 checked>C6<br>
<input type=checkbox name=C7 checked>C7<br>
<input type=checkbox name=C8 checked>C8<br>
<input type=checkbox name=C9 checked>C9<br>
<br>
<input type=button value="全部选中" onClick="checkAll()"><br>
<input type=button value="全部不选" onClick="uncheckAll()"><br>
<input type=button value="选择转换" onClick="switchAll()"><br>
</form>