复选框全选

html:

 

<input type="checkbox" name='selectAll' />全选
<input type='checkbox' name='imgindex' value='0' />1
<input type='checkbox' name='imgindex' value='1' />2

 js：

<script type="text/javascript">
var selectAll=document.getElementsByName('selectAll')[0];
var imgindex=document.getElementsByName('imgindex');
selectAll.onclick=function(e){
	var flag=Boolean(selectAll.checked);
	for ( var i = 0; i < imgindex.length; i++) {
		var ele = imgindex[i];
		ele.checked=flag;
	}
}
</script>

 onclick的function也可这样写

if (selectAll.checked) {
		for ( var i = 0; i < imgindex.length; i++) {
			var ele = imgindex[i];
			ele.checked=true;
		}
	}else{
		for ( var i = 0; i < imgindex.length; i++) {
			var ele = imgindex[i];
			ele.checked=false;
		}
	}