title: changing z index of marker on hover to make it visible
body: <p>I'm trying to make the marker i'm currently hovering on have a greater z-index than the others, so that even if it's hidden by other markers it'll gain full visibility when I hover on it.</p>
  
  <p>On click of any marker i want to do the same . </p>
  
  <pre><code>  google.maps.event.addListener(this.marker, 'mouseover', function() {
              this.old_ZIndex = this.getZIndex(); //trying to get the current z- index
              console.log(this.old_ZIndex); //this is undefined: why?
              this.setZIndex(this.old_ZIndex + 100); //setting a higher z-index than all other  markers
              console.log("the old z index is ",this.old_ZIndex);
          });
  </code></pre>
  
  <p>But with this i would be infinitely increase the z index .. is there some other way in which I can have the to revert back when i hover or click any other marker . .</p>
  
  <p>Or is there any better way to implement it ??</p>