Is it not possible to use HTML entities in a title attribute?

Question

The above screengrab is from Firefox. The cursor is hovering over the yellow spot at the left hand side of the image. It is an <img> element (well actually it's an image together with an image map containing a single circular <area> element, but I assume this distinction is unimportant) that has been created and styled in JavaScript, including the application of a title attribute (constructed by cutting and gluing strings). How can I get this to behave and show the intended character, an en dash, instead of –? It works for innerHTML (the text "Barrow-In-Furness" in the top middle-left is a div that was also created using JavaScript, and its innerHTML set.)

Edit: In response to question of Domenic: Here is the JavaScript function that builds and applies the title attribute (in addition to performing other jobs):

var StyleLinkMarker = function (LinkNumber, EltA, EltI) {
    var AltText = LocationName[LinkStart[LinkNumber]] +
                  " to " +
                  LocationName[LinkEnd[LinkNumber]];
    if (!EltA) {
        EltA = document.getElementById("link_marker_area" + LinkNumber);
        EltI = document.getElementById("link_marker_img" + LinkNumber);
    }
    if (LinkStatus[LinkNumber] === 9) {
        var CanBuyLinkCode = BoardPreviewMode ? 0 : CanBuyLink(LinkNumber);
        if (CanBuyLinkCode === 0) {
            EltI.src = ImagePath + "icon-buylink-yes.png";
            AltText += " (you can buy this " + LinkAltTextDescription + ")";
        } else {
            EltI.src = ImagePath + "icon-buylink-no.png";
            AltText += " (you cannot buy this " + LinkAltTextDescription;
            AltText += CanBuyLinkCode === 1 ?
                       ", because you aren't connected to it)" :
                       ", because you would have to buy coal from the Demand Track, and you can't afford to do that)";
        }
    } else if ( LinkStatus[LinkNumber] === 8 ||
                (LinkStatus[LinkNumber] >= 0 && LinkStatus[LinkNumber] <= 4)
                ) {
        EltI.src = ImagePath + "i" + LinkStatus[LinkNumber] + ".png";
        if (LinkStatus[LinkNumber] === 8) {
            AltText += " (orphan " + LinkAltTextDescription + ")";
        } else {
            AltText += " (" +
                       LinkAltTextDescription +
                       " owned by " +
                       PersonReference(LinkStatus[LinkNumber]) +
                       ")";
        }
    } else {
        throw "Unexpected Link Status";
    }
    EltA.alt = AltText;
    EltA.title = AltText;
};

LocationName is as follows:

var LocationName = [
    "Barrow–In–Furness", "Birkenhead",                "Blackburn", "Blackpool",
                           "Bolton",    "Burnley",                     "Bury",     "Colne",
                   "Ellesmere Port",  "Fleetwood",                "Lancaster", "Liverpool",
                     "Macclesfield", "Manchester",             "The Midlands", "Northwich",
                           "Oldham",    "Preston",                 "Rochdale",  "Scotland",
                        "Southport",  "Stockport", "Warrington & Runcorn",     "Wigan",
                        "Yorkshire"
];

Answer 1

You aren't setting the title attribute, you are setting the title property, which expects text and not HTML (although the setAttribute method also expects a text string).

Generally speaking, when dealing with DOM manipulation, you provide text and not HTML. .innerHTML is the notable exception to this rule.