Checkboxes in table1(#tbl1) in jsp created dynamically using ajax and jquery with id like : id="123" (firstId)

```
$.each(json, function(idx, obj) {

$("#tbl1").append('<input type="checkbox" id='+obj.firstId+' onclick=nextPopulate('+obj.firstId+'); >'); }

```

In table2(#tbl2), checkboxes is created on check of checkboxes in tbl1 and whose id will be : 

id="123-001" (firstId-secondId)

```
$.each(json, function(idx, obj) {

$("#tbl2").append('<input type="checkbox" id="'+firstId+'-'+secondId+'" >'); }

```

In my javascript, i'm using an ajax call to remove checkboxes in tbl2 if checkbox in tbl1 is unchecked.

The id's of second set of checkboxes will be like : "123-001" ,"123-002", "123-003", "456-001"

So,to remove all checkboxes from tbl2 whose id starts with firstId (123), if checkbox with id 123 is unchecked in tbl1.

How can i do this ? 

I can use .empty(). But how to specify id as 'starts with firstId' (123)

I'm trying:

```
if(!($('#'+firstId).is(':checked'))){

    $('#'+firstId'-').empty();

```