js实现checkbox全选
<script language= 'javascript '>
function selectall(){var check_id = document.getElementsByName("items[]");
if(check_id != null){
for (var i=0; i<check_id.length; i++){
check_id[i].checked = !check_id[i].checked;
}
}
}
</script>
<div>
<form name= 'myform '>
<input type= 'checkbox ' name= 'items[] ' value= 'a '> a <br/>
<input type= 'checkbox ' name= 'items[] ' value= 'b '> b<br/>
<input type= 'checkbox ' name= 'items[] ' value= 'c '> c <br/>
<input type= 'checkbox ' name= 'items[] ' value= 'd '> d<br/>
<input type= "checkbox " name= 'allCheck ' onclick= "selectall()"> 全选
</form>
</div>