Javascriptで縦横チェックボックスに一気にチェック付けるやつ

<SCRIPT TYPE="text/javascript">
function BoxCheckedCircle(circle){
	var elements = document.getElementsByClassName(circle);
	for (i = 0; i < elements.length; i++) {
		elements[i].checked = true;
	}
}
function BoxCheckedCommu(commu){
	var elements = document.getElementsByClassName(commu);
	for (i = 0; i < elements.length; i++) {
		elements[i].checked = true;
	}
}
</SCRIPT>

<FORM NAME="form1">

<table border="1">
<tr>
<td></td>
<td></td>
<td>サークル１</td>
<td>サークル２</td>
<td>サークル３</td>
</tr>

<tr>
<td></td>
<td></td>
<td><INPUT TYPE="button" onClick="BoxCheckedCircle('circle_1');" VALUE="全て選択"></td>
<td><INPUT TYPE="button" onClick="BoxCheckedCircle('circle_2');" VALUE="全て選択"></td>
<td><INPUT TYPE="button" onClick="BoxCheckedCircle('circle_3');" VALUE="全て選択"></td>
</tr>

<tr>
<td>店舗１</td>
<td><INPUT TYPE="button" onClick="BoxCheckedCommu('commu_1');" VALUE="全て選択"></td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_1_circle_1" class="commu_1 circle_1"> </td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_1_circle_2" class="commu_1 circle_2"> </td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_1_circle_3" class="commu_1 circle_3"> </td>
</tr>

<tr>
<td>店舗２</td>
<td><INPUT TYPE="button" onClick="BoxCheckedCommu('commu_2');" VALUE="全て選択"></td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_2_circle_1" class="commu_2 circle_1"> </td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_2_circle_2" class="commu_2 circle_2"> </td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_2_circle_3" class="commu_2 circle_3"> </td>
</tr>

<tr>
<td>店舗３</td>
<td><INPUT TYPE="button" onClick="BoxCheckedCommu('commu_3');" VALUE="全て選択"></td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_3_circle_1" class="commu_3 circle_1"> </td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_3_circle_2" class="commu_3 circle_2"> </td>
<td><INPUT TYPE="checkbox" NAME="chk" VALUE="commu_3_circle_3" class="commu_3 circle_3"> </td>
</tr>

</FORM>