[thelist] PNG support in IE, using WebFX script

[Chris W. Parker]

hi.

recently i discovered a script that allows IE to support PNG's as they
were intended to be used. the script works by detecting what browser the
client is using and adding an IE filter if the browser is found to be
IE/Win32. all other browsers are left alone.

the problem is that IE complains about one line in the .htc file i use.

here is the entire script... (watch wrap)

<public:component>
<public:attach event="onpropertychange" onevent="propertyChanged()" />
<script>

var supported = /MSIE (5\.5)|[6789]/.test(navigator.userAgent) &&
navigator.platform == "Win32";
var realSrc;
var blankSrc = "images/spacer.gif";

if (supported) fixImage();

function propertyChanged() {
   if (!supported) return;

   var pName = event.propertyName;
   if (pName != "src") return;
   // if not set to blank
   if ( ! new RegExp(blankSrc).test(src))
      fixImage();
};

function fixImage() {
   // get src
   var src = element.src;

   // check for real change
   if (src == realSrc) {
      element.src = blankSrc;
      return;
   }

   if ( ! new RegExp(blankSrc).test(src)) {
      // backup old src
      realSrc = src;
   }

   // test for png
   if ( /\.png$/.test( realSrc.toLowerCase() ) ) {
      // set blank image
      element.src = blankSrc;
      // set filter
      element.runtimeStyle.filter =
"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" +
                                     src + "',sizingMethod='scale')";
   }
   else {
      // remove filter
      element.runtimeStyle.filter = "";
   }
}

</script>
</public:component>

the line in question is #37 which reads...

   if ( /\.png$/.test( realSrc.toLowerCase() ) ) {

and the error IE is reporting is "'realSrc' is null or not an object".

i want that to go away and i'm not sure what the problem is. the funny
part (funny strange, not funny haha) is that it works fine (no error
reported) on a basic test page i use but not on the "production" page.
although one page has a lot more markup the script is executed in the
same way.

any ideas?



chris.

p.s. no links were provided because both pages are on a private server.
i can move them somewhere public if necessary.