rem: this.appLauncher.Cancel(); 
add: try { this.appLauncher.Cancel(); } catch( exception ) { } 
context:     onCancel : function () {        // Cancel app launcher.        this.appLauncher.Cancel();            // Close up dialog by returning true.        return true;    },
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/3c0cfcea120ad5eb0f470f8409cbe2932728682b/helperAppLauncher.js/clean/xpfe/components/ucth/resources/helperAppLauncher.js