Zac Barton reports that IEs4Lin does not like document.body.filters. (Confirmed

via forums for the product.) Although this is a bug in that browser, this work
around will allow OL to work for that browser, according to testing.


git-svn-id: http://svn.openlayers.org/trunk/openlayers@1700 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Util.js

@@ -231,8 +231,19 @@ OpenLayers.Util.onImageLoadError = function() {
 OpenLayers.Util.alphaHack = function() {
     var arVersion = navigator.appVersion.split("MSIE");
     var version = parseFloat(arVersion[1]);
+    var filter = false;
     
-    return ( (document.body.filters) &&
+    // IEs4Lin dies when trying to access document.body.filters, because 
+    // the property is there, but requires a DLL that can't be provided. This
+    // means that we need to wrap this in a try/catch so that this can
+    // continue.
+    
+    try { 
+        filter = document.body.filters;
+    } catch (e) {
+    }    
+    
+    return ( filter &&
                       (version >= 5.5) && (version < 7) );
 }