<div dir="ltr">I second Alexandre, i think you'll need to add some layers on the constructor. The overview control expects a base layer to be set or that you supply some, otherwise it'll have nothing to display.</div>
<div class="gmail_extra"><br><br><div class="gmail_quote">2013/7/10 Alexandre Dubé <span dir="ltr"><<a href="mailto:adube@mapgears.com" target="_blank">adube@mapgears.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

  
    
  
  <div bgcolor="#FFFFFF" text="#000000">
    <div>Hi Robert,<br>
      <br>
        You could try to create your overview map with its own layers:<br>
      <br>
        new OpenLayers.Control.OverviewMap({<br>
          layers: [<br>
            new OpenLayers.Layer...<br>
          ]<br>
        });<br>
      <br>
      HTH,<br>
      <br>
      Alexandre<div class="im"><br>
      <br>
      <br>
      On 13-07-10 07:34 AM, Rob Hyx wrote:<br>
    </div></div><div class="im">
    <blockquote type="cite">
      <div dir="ltr"><span style="font-size:medium;font-family:Helvetica">Alexandre,
          thanks for your reply.</span>
        <div style="font-size:medium;font-family:Helvetica"><br>
        </div>
        <div style="font-size:medium;font-family:Helvetica">
          I did try adding the control in via Firebug just from the
          console after the page has fully loaded and I get the same
          error. From looking at the call stack in FB:</div>
        <div style="font-size:medium;font-family:Helvetica">
          <br>
        </div>
        <div style="font-size:medium;font-family:Helvetica">
          <div>zoomToExtent(bounds=-180,-90,180,90 { left=-180,
            bottom=-90, right=180, more...}, closest=undefined)</div>
          <div>zoomToMaxExtent(options=undefined)</div>
          <div>createMap()</div>
          <div>update()</div>
          <div>draw()</div>
          <div>addControlToMap(control=Object { layers=[1],
            handlers={...}, displayClass="olControlOverviewMap",
            more...}, px=undefined)</div>
          <div>addControl(control=Object { layers=[1], handlers={...},
            displayClass="olControlOverviewMap", more...}, px=undefined)<br>
            <br>
          </div>
          <div>So it's the call to zoomToMaxExtent() in createMap() that
            does it. I can see in draw() that there are layers being
            assigned to the overview (the baseLayer of the the actual
            map object), but no baseLayer property.<br>
          </div>
        </div>
      </div>
    </blockquote>
    <br>
    <br>
    </div><div class="im"><pre cols="72">-- 
Alexandre Dubé
Mapgears
<a href="http://www.mapgears.com" target="_blank">www.mapgears.com</a>
</pre>
  </div></div>

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