<!DOCTYPE html>
<html>
<body>
<p id="myP" style="border-top: 5px solid red;">Click the button to get the value of my top border.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var x = document.getElementById("myP").style.borderTop;
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>