checkboxの全選択とキャンセルの例

<script language="JavaScript" type="text/javascript">
	function $(objName) {
		return document.getElementById(objName);
	}
	function selectItems(checkboxName) {
		var isNeedCheck = false;
		for(var i = 0; i < 10; i++) {
			var obj = $(checkboxName + (i + 1));
			if (obj) {
				if (!obj.checked) {
					isNeedCheck = true;
					break;
				}
			} else {
				break;
			}
		}
		for(var i = 0; i < 10; i++) {
			var obj = $(checkboxName + (i + 1));
			if (obj) {
				obj.checked = isNeedCheck;
			}
		}
	}
</script>
<table>
	<tr>
		<td>
			<input type="button" name="allSelect" onclick=selectItems('resultCheckbox');  value="  " >
		</td>
	</tr>
	<tr>
		<td>
			<input type="checkbox" name="resultCheckbox1">	
		</td>
	</tr>
	<tr>
		<td>
			<input type="checkbox" name="resultCheckbox2">	
		</td>
	</tr>
	<tr>
		<td>
			<input type="checkbox" name="resultCheckbox3">	
		</td>
	</tr>
	<tr>
		<td>
			<input type="checkbox" name="resultCheckbox4">	
		</td>
	</tr>
	<tr>
		<td>
			<input type="checkbox" name="resultCheckbox5">	
		</td>
	</tr>
	<tr>
		<td>
			<input type="checkbox" name="resultCheckbox6">	
		</td>
	</tr>
</table>