title: Creating a custom button in firefox (using the custom buttons addon) does not allow me to resize the button image
body: <p>I have successfully created my own custom button in firefox and it does what i need.  So then i placed a custom icon onto it via the code below (which works as I wanted), the only problem with it is that my source image may be bigger or smaller than the size I actually want it to be (to match the other icons in the toolbar).  So what I want to do is resize the image in the code below somehow to a hard coded size and optionally to the size of the other button's icons.</p>
  
  <p>I have done a lot of googling and I could not find any working solution besides resizing the image in an image editor and using that resized version.  All my commented out code below are just some of the things I tried to get the image to resize.  None worked.</p>
  
  <p>Another thing I am wondering is where can i look for good documentation on what functions and properties are available to me for making custom buttons.  I tried the custom buttons website and it seems pretty sparse on documentation.  Ie. i'm basically just guessing at this point as google hasn't come up with any more good examples that i haven't already tried.</p>
  
  <pre><code>var profilePath="file:\\" + Components.classes["@mozilla.org/file/directory_service;1"].getService( Components.interfaces.nsIProperties).get("ProfD", Components.interfaces.nsIFile).path
  var myImageDirRelativePath="/testicons/"
  
  var myImage="Next.ico"
  
  this.image=profilePath + myImageDirRelativePath + myImage
  
  //this.style.width=500
  //this.style.height=500
  
  //this.width=50
  //this.height=40
  
  //this.image.height=5
  //this.image.width=5
  
  //this.region=new rect(0px, 24px, 24px, 0px)
  </code></pre>
  
  <p>I also tried setting the following property:</p>
  
  <pre><code>.custombutton                  
    {-moz-image-region: rect( 0px 24px 24px  0px);}
  </code></pre>
  
  <p>which didn't work.</p>