rem: field.setAttribute( "value", url ); 
add: field.setAttribute( "value", fileSpec.nativePath ); 
context: function PrefNavSelectFile() {    // Get filespecwithui component.                var fileSpec = createInstance( "component://netscape/filespecwithui", "nsIFileSpecWithUI" );    try {        var url = fileSpec.chooseFile( "" );        var field = document.getElementById( "pref:string:browser.startup.homepage" );        field.setAttribute( "value", url );    }    catch( exception ) {        // Just a cancel, probably.    }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/421d32d4fd4e544bd2a1a885a12c9b0399dd11f9/PrefsWindow.js/clean/xpfe/components/prefwindow/resources/content/PrefsWindow.js