JSFiddle - React, Tailwind, and code Playground

http://stackoverflow.com/questions/16504905/download-arrow-assist-download-a-file-and-have-an-arrow-point-where-it-is

HTML

<button onclick="download()"> download </button>

<div id="arrow-chrome"></div>
<div id="arrow-ie"></div>
<div id="arrow-safari-mac"></div>

CSS

#arrow-chrome, #arrow-ie, #arrow-safari-mac {
    position: fixed;
    display: none;
    z-index: 10;
    height: 309px;
    width: 186px;
}

#arrow-chrome {
    bottom: 10px;
    left: 20px;
    background: url("http://cdn.mediafire.com/images/backgrounds/download/dlpointers/arrow_down.png") no-repeat scroll center center transparent;
}

#arrow-ie {
    bottom: 10px;
    left: 50%;
    margin-left: -140px;
    background: url("http://cdn.mediafire.com/images/backgrounds/download/dlpointers/arrow_down.png") no-repeat scroll center center transparent;
}

#arrow-safari-mac {
    top: 10px;
    right: 10px;
    z-index: 100 !important;
    background: url("http://cdn.mediafire.com/images/backgrounds/download/dlpointers/arrow_up.png") no-repeat scroll center center transparent;
}

html,body {
    width:100%;
    height:100%;
}

JavaScript

navigator.sayswho= (function(){
    var N= navigator.appName, ua= navigator.userAgent, tem;
    var M= ua.match(/(opera|chrome|safari|firefox|msie)\/?\s*(\.?\d+(\.\d+)*)/i);
    if(M && (tem= ua.match(/version\/([\.\d]+)/i))!= null) M[2]= tem[1];
    M= M? [M[1], M[2]]: [N, navigator.appVersion,'-?'];
    return M;
})();
// http://stackoverflow.com/questions/2400935/browser-detection-in-javascript#2401861
//console.log(navigator.sayswho);

function auK(auy) {
    $(auy).fadeIn(750, function () {
        setTimeout(function () {
            $(auy).fadeOut(1000);
        }, 10000);
    });
}

function download() {
    if (navigator.sayswho[0].toLowerCase() == 'chrome') {
      auK('#arrow-chrome');
    }
    if ((navigator.sayswho[0].toLowerCase() == 'msie') && (navigator.sayswho[1] == 9.0)) {
      auK('#arrow-ie');
    }
    if (navigator.sayswho[0].toLowerCase() == 'safari' && (navigator.platform.toUpperCase().indexOf('MAC')>=0) ) {
      auK('#arrow-safari-mac');
    }
}