Append Next Integer To A Value Going In To MongoDB With JS

I am using node.js with mongodb have a <select><option> Box holding values,

Each value will be entered in to the DB if it is selected.

First-
Second-
Third-

If First- is selected I want it to be entered to the DB as First-1

If First has one entry in the DB I want the second entry to be entered to the DB as First-2 and so on.

I can not come up with a good plan on how to achieve this.

Any ideas?

Here is my function filling the select option box

 // Fill Combobox with items in the array
function populateCombo() {
    var combo = '';
    var comboContent = new Array('<option value="" disabled selected>Select Type', '<option value="LP-Bom">Bombardier', '<option value="LP-Gul">Gulfstream', '<option value="LP-Pil">Pilatus');

 $.each(comboContent, function( index, value){
    combo += value + '</option>';
                   });
   // Inject the whole content string into our existing HTML table
        $('#manuType').html(combo);
};

Here is my function entering data to the database

        // Gather new data to be entered to DB
        var newDrawing = {
            'lpNumber': $('#addDrawing fieldset select#manuType').val()
        }

What is the best way to attach a int value to the end of each entry to the DB