rem: try { printProgress.unregisterListener(progressListener); printProgress = null; }  catch( exception ) {} 
add: try { printProgress.unregisterListener(progressListener); printProgress = null; } catch(ex){} 
context: function onUnload() {  if (printProgress)  {   try    {     printProgress.unregisterListener(progressListener);     printProgress = null;   }       catch( exception ) {}  }}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/2abcfc3bd3437e146a421dc9404a6e59b89a511a/printProgress.js/clean/xpfe/global/resources/content/printProgress.js