
Code
<SCRIPT LANGUAGE="JavaScript">
function ck(b)
{
var input = document.getElementsByTagName("input");
for (var i=0;i<input.length ;i++ )
{
if(input[i].type=="checkbox")
input[i].checked = b;
}
}
</SCRIPT>
<INPUT TYPE="checkbox" NAME="a">1
<INPUT TYPE="checkbox" NAME="a">2
<INPUT TYPE="checkbox" NAME="a">3
<INPUT TYPE="checkbox" NAME="a">4
<INPUT TYPE="checkbox" NAME="a">5<BR>
<input type="button" onclick="ck(true)" value="全选">
<input type="button" onclick="ck(false)" value="取消全选">
<input type="button" name="checkAllOk" value="全选" onclick="checkAll()" />
使用按钮时,要注意type=""的类型,不能为submit,应该是button