kryssa i alla checkboxar?

Går denna att göra lite smidigare?

<script type="text/javascript">

var boxeschecked = true;

function checkboxctrl(){
if(boxeschecked==true){
boxeschecked=false;
checkAll()
}else{
boxeschecked=true;
uncheckAll()
   }
};

function checkAll(){
     for(var i=0; i<document.foo.elements.length; i++){
          if(document.foo.elements[i].type == "checkbox")
               document.foo.elements[i].checked = true;
     }
};

function uncheckAll(){
     for(var i=0; i<document.foo.elements.length; i++){
          if(document.foo.elements[i].type == "checkbox")
               document.foo.elements[i].checked = false;
     }
};

</script>

Markera/avmarkera <input type="checkbox" onClick="checkboxctrl();">
<br>
<form name="foo">
	<input type="checkbox" value="0"> 
	<input type="checkbox" value="1"> 
	<input type="checkbox" value="2"> 
	<input type="checkbox" value="3"> 
</form>

Yes:

<script type="text/javascript">

function checkboxctrl(){
    var elms = document.forms["foo"].elements,
	iLen = elms.length;

    while (iLen-->0)
	elms[iLen].type == "checkbox" && (elms[iLen].checked = !elms[iLen].checked);
}

</script>

Markera/avmarkera <input type="checkbox" onClick="checkboxctrl();">
<br>
<form name="foo">
	<input type="checkbox" value="0"> 
	<input type="checkbox" value="1"> 
	<input type="checkbox" value="2"> 
	<input type="checkbox" value="3"> 
</form>

:)