DhtmlxCombo checkbox

I created a DhtmlxCombo checkbox using the following code:

myQueryTerm = new dhtmlXCombo(“QueryTerm”, “queryterm1”, 130, “checkbox”);

I want to use the combo checkbox to filter a dhtmlxgrid

I am using the following code:

myQueryTerm.attachEvent(“onCheck”, function(value){
var checked_array = myQueryTerm.getChecked();
if(checked_array == “”)

when I check an option in the checkbox it successfully filters the grid. however if I check a second box it loses the original filter and only filters the new item.

I am at a complete loss. Please help.

Unfortunately creating a multiselect filter for the grid is much more complex and requires more detailes.
There is no ready solution. Please, open ticket at support.dhtmlx.com and add a request so the staff can help you to achieve the required functionality.