[html] How to change the style of the title attribute inside an anchor tag?

I thought i'd post my 20 lines JavaScript solution here. It is not perfect, but may be useful for some depending on what you need from your tooltips.

When to use it

• Automatically styles the tooltip for all HTML elements with a TITLE attribute defined (this includes elements dynamically added to the document in the future)
• No Javascript/HTML changes or hacks required for every tooltip (just the TITLE attribute, semantically clear)
• Very light (adds about 300 bytes gzipped and minified)
• You want only a very basic styleable tooltip

When NOT to use

• Requires jQuery, so do not use if you don't use jQuery
• Bad support for nested elements that both have tooltips
• You need more than one tooltip on the screen at the same time
• You need the tooltip to disappear after some time

The code

// Use a closure to keep vars out of global scope
(function () {
    var ID = "tooltip", CLS_ON = "tooltip_ON", FOLLOW = true,
    DATA = "_tooltip", OFFSET_X = 20, OFFSET_Y = 10,
    showAt = function (e) {
        var ntop = e.pageY + OFFSET_Y, nleft = e.pageX + OFFSET_X;
        $("#" + ID).html($(e.target).data(DATA)).css({
            position: "absolute", top: ntop, left: nleft
        }).show();
    };
    $(document).on("mouseenter", "*[title]", function (e) {
        $(this).data(DATA, $(this).attr("title"));
        $(this).removeAttr("title").addClass(CLS_ON);
        $("<div id='" + ID + "' />").appendTo("body");
        showAt(e);
    });
    $(document).on("mouseleave", "." + CLS_ON, function (e) {
        $(this).attr("title", $(this).data(DATA)).removeClass(CLS_ON);
        $("#" + ID).remove();
    });
    if (FOLLOW) { $(document).on("mousemove", "." + CLS_ON, showAt); }
}());

Paste it anywhere, it should work even when you run this code before the DOM is ready (it just won't show your tooltips until DOM is ready).

Customize

You can change the var declarations on the second line to customize it a bit.

var ID = "tooltip"; // The ID of the styleable tooltip
var CLS_ON = "tooltip_ON"; // Does not matter, make it somewhat unique
var FOLLOW = true; // TRUE to enable mouse following, FALSE to have static tooltips
var DATA = "_tooltip"; // Does not matter, make it somewhat unique
var OFFSET_X = 20, OFFSET_Y = 10; // Tooltip's distance to the cursor

Style

You can now style your tooltips using the following CSS:

#tooltip {
    background: #fff;
    border: 1px solid red;
    padding: 3px 10px;
}