JavaScript: Set border radius

How can I set the -moz-border-radius with pure JavaScript (no jQuery, no plugins etc)?

document.getElementById(开发者_如何转开发'id')

Try:

document.getElementById('id').style.borderRadius = '1em'; // w3c
document.getElementById('id').style.MozBorderRadius = '1em'; // mozilla

But why not do it in a stylesheet?

var myElementStyle = document.getElementById('id').style;

myElementStyle.borderRadius = '1em'; // standard
myElementStyle.MozBorderRadius = '1em'; // Mozilla
myElementStyle.WebkitBorderRadius = '1em'; // WebKit