I have found here some questions about my problem, but I can't use it. I will change a css property of during click on them via JS, JQuery
 <!DOCTYPE HTML>
<html>
<head>
    <meta charset="utf-8">
    <script src="../scripts/jquery-1.11.1.min.js"></script>
    <link rel="stylesheet" type="text/css" href="../css/styles.css">
    <script src="../scripts/javascript.js"></script>
</head>
<body>
<div class="osn">
<span>Green</span>
</div>
<div class="osb">
    <span>Red</span>
</div>
</body>
</html>
<script>
/*$( document ).ready(function () { 
    $(".osn").mouseover(function() { 
        uploadcss()
        });
});*/
$( document ).ready(function () { 
    $(".osn").click(function addcss (csslink){});
});
</script>
and my javascript.js
function uploadcss() {$(".osb").css("border","15px solid blue")};
function downloadcss() {$(".osb").css("border","5px solid red")};
function addcss (csslink) {
    var csslink = document.cretaeElement ("link");
    csslink.rel = "stylesheet";
    csslink.type = "text/css";
    csslink.href="../css/test.css";
}
And it's doesn't work :( Why?
 
     
     
    