I have the following html code:

```
<div class="stats" id="sdell_ac359636_ert_stats">
<var class="time" id="sdell_ac359636_time" style="color: red; font-size: 18px;">00:00</var> <var class="user" id="sdell_ac359636_select" style="display: none;">anything</var>
<div class="user_who_left"><span class="left_list_other_user">anything</span></div>
</div>

```

The class "user" is fixed, the id changes each page, but it always ends with "\_select". Is not my website, so I cannot control that.

What I would like to do is to insert the id "sdell\_ac359636\_select" into the default value of the following js form:

```
var idDivText = this._getRandomID();
        var idDivBtn = this._getRandomID();
        layer.innerHTML += '<input type="text" value="!!!id goes here!!!" id="'+idDivText+'"/>';
        layer.innerHTML += '<input id="'+idDivBtn+'" type="button" value="START"/>';

```

Trying for a while with no "luck".