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/*  **********************************************  */
/*  For inclusion in the HEAD of the "viewer" page  */
/*  **********************************************  */

/*  In a previous implementation, scripts running in "document" pages would 
    load a "viewer" page that contained a frameset in which to re-present 
    the document page with a banner and table of contents (TOC). The 
    document at 

        http://hostname/path/document.htm?search#hash 

    would load 

        http://hostname/viewer.htm?doc=path/document.htm&bm=hash&search 

    To support other sites' links to this site's VIEWER.HTM now that the 
    implementation has changed, this script reverses the redirection.  */

/*  **********  */
/*  Validation  */

function IsPlausibleDocArgument (Doc)
{
    /*  All paths that are valid for redirection will begin with a 
        lower-case letter.  */

    var first = Doc.charAt (0);
    return 'a' <= first && first <= 'z';
}

/*  *********************  */
/*  Global Initialisation  */

/*  Do nothing if we seem to be in someone else's presentation, e.g., a 
    search engine's cache, or if we don't have some minimal scripting 
    support.  */

if (IsBadHostName () || IsLowScriptSupport ()) {
    /*  do nothing  */
}

/*  If we are somehow being presented in another window, then force our way 
    to the top.  */

else if (window != window.top) {
    window.top.location.replace (window.location);
}

/*  Ordinarily, replace "viewer.htm" with whatever is indicated in the "doc" 
    argument, remove the "doc" argument, change the "bm" argument to a 
    bookmark, keep everything else in the search string, and then redirect 
    the browser.  */

else {
    var search = new ParsedSearch (window.location.search);
    var pathname = search.Delete (sDocumentArgumentName);
    if (pathname != null && IsPlausibleDocArgument (pathname)) {
        var hash = search.Delete (sBookmarkArgumentName);
        window.location.replace (new LocalUrl (pathname, search, hash));
    }
}

/*  Copyright © 2007-2012. Geoff Chappell. All rights reserved.  */

//-->