var names = []; 
names["none"] = "None Available";

// text formats.
names["doc"] = "Microsoft Word (*.doc)";
names["pdf"] = "Portable Document Format (*.pdf)";
names["odt"] = "OpenDocument Text (*.odt)";
names["sxw"] = "OpenOffice.org 1.0 Text (*.sxw)";
names["rtf"] = "Rich Text Format (*.rtf)";
names["wpd"] = "WordPerfect (*.wpd)";
names["txt"] = "Plain Text (*.txt)";
names["wiki"] = "MediaWiki wikitext (*.wiki)";

names["html"] = "HTML1 (*.html)";
names["htm"] = "HTML1 (*.html)";

// spread sheet formats.
names["ods"] = "OpenDocument Spreadsheet (*.ods)";
names["sxc"] = "OpenOffice.org 1.0 Spreadsheet (*.sxc)";
names["xls"] = "Microsoft Excel (*.xls)";
names["csv"] = "Comma-Separated Values (*.csv)";
names["tsv"] = "Tab-Separated Values (*.tsv)";

// slideshow formats.
names["odp"] = "OpenDocument Presentation (*.odp)";
names["sxi"] = "OpenOffice.org 1.0 Presentation (*.sxi)";
names["ppt"] = "Microsoft PowerPoint (*.ppt)";
names["swf"] = "Macromedia Flash (*.swf)";

// office drawing formats.
names["odg"] = "OpenDocument Drawing (*.odg)";
names["svg"] = "Scalable Vector Graphics (*.svg)";

// OpenXML formats.
names["docx"] = "Microsoft Word 2007 (*.docx)";
names["xlsx"] = "Microsoft Excel 2007 (*.xlsx)";
names["pptx"] = "Microsoft PowerPoint 2007 (*.pptx)";


function nullOptions(aMenu){
    aMenu.options.length = 0;
}
 

function fileChange(obj) {
    var ext_sel = document.getElementById("to_ext");
    nullOptions(ext_sel);
    

    var path = obj.value;
    if (path == "") {
        return;
    }
    var loc = path.lastIndexOf('.');
    if (loc == -1) {
        alert("Warning: The file you have selected for conversion does not have a file extension.");
        return;
    }
    
    var ext = path.substr(loc + 1).toLowerCase();     
    
    var options = [];
    switch (ext) {
        case "docx":
        case "odt":
        case "sxw":
        case "rtf":
        case "doc":
        case "wpd":
        case "txt":
        case "html":
        case "htm":
            options = ["doc", "docx", "pdf", "odt", "sxw", "rtf", "txt", "html", "wiki"];
            break;
        case "xlsx":
        case "ods":
        case "sxc":
        case "xls":
        case "csv":
        case "tsv":
            options = ["pdf", "ods", "sxc", "xls", "csv", "tsv", "html"];
            break;
        case "pptx":                
        case "odp":
        case "sxi":
        case "ppt":
             options = ["pdf", "swf", "odp", "sxi", "ppt", "html"];
             break;
        case "odg":
            options = ["svg", "swf"];
            break;
        default:
            alert("Warning: your selected file does not have a recognized extension.");
        break;
    }
    
    var i = 0; 
    var opts = options;
    if (opts.length == 0) {
        opts = ["none"];
    }
    for (var nm in opts) {
        // remove from the to-format list the format that is being converted from.
        if (opts[nm] != ext) {
            with (ext_sel) {
                options[i] = new Option(names[opts[nm]], opts[nm]);
            }
            i++;
        }
    }
                         
}