js实现checkbox多级选择
    <script type="text/javascript"> 	
	function chose(obj){
	  var funid= obj.id;
	  var f = window.document.sysRoleForm;
	  var ele = f.elements;
	  var len = funid.length;
	  var lent = len/3;
	  var endsub = len-3;
	  var count = 0;
	  var tolcount =0;
	  switch(obj.checked){
		case true:{
				   for (var i = 0; i < ele.length; i++) {
						 var name = ele[i].id;
						 if(name.indexOf(funid)==0){
							 document.sysRoleForm.all(name).checked=true;
						 }
					 }
					 for(i=1;i<lent;i++){
						var sub = funid.substring(0,endsub);
						endsub=endsub-3;
					   document.sysRoleForm.all(sub).checked=true;
					}
					break;
		}
		case false:{
					for (var i = 0; i < ele.length; i++) {
						 var name = ele[i].id;
						 var nlen = name.length;
						 if(name.indexOf(funid)==0){
							document.sysRoleForm.all(name).checked=false;
						 }
						 if(nlen>3){
							var  subname = name.substring(0,nlen-3);
							if(nlen==len && funid.indexOf(subname)==0){
								count = count +1 ;
							}
							if(nlen==len && funid.indexOf(subname)==0 && document.sysRoleForm.all(name).checked==false){
								tolcount = tolcount +1 ;
							}
						  }
					}
					if(count==tolcount && count!=0 && tolcount !=0){
						subfunid = funid.substring(0,endsub)
						document.sysRoleForm.all(subfunid).checked=false;
					}
					break;
				}
		}
	}
</script>