<script language="JavaScript" type="text/javascript">
<!--

var formblock;
var forminputs;

function prepare() {
	formblock = document.getElementById('mix_form');
	forminputs = formblock.getElementsByTagName('input');
}

function select_all(name, checker_id) {
	for (i = 0; i < forminputs.length; i++) {
		// regex here to check name attribute
		var regex = new RegExp(name, "i");
		if (regex.test(forminputs[i].getAttribute('name'))) {
			if(document.getElementById(checker_id).checked == 1) {
				forminputs[i].checked = true;
			} else {
				forminputs[i].checked = false;
			}
		}
	}
	if(document.getElementById(checker_id).checked == 1) {
		document.getElementById(checker_id).checked = 1;
	} else {
		document.getElementById(checker_id).checked = 0;
	}
} 
//-->
</script>
<input type="checkbox" id="checkker_name" onClick="select_all('list','checkker_name');">

<input type="checkbox" name="list[]" value="1">
<input type="checkbox" name="list[]" value="2">
<input type="checkbox" name="list[]" value="3">