function rot13(input) {
	var coding = 'ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMabcdefghijklmnopqrstuvwxyzabcdefghijklm';

	for (var text = '',i=0;i<input.length;i++) {
		character = input.charAt(i);
		position = coding.indexOf(character);
		if (position > -1)
			character = coding.charAt(position + 13);
		text += character;
	}

	return text;
}

function ontRot() {
	if (this.href.indexOf('mailto:')!=0) {
		this.href=rot13(this.href);
	}
}

$("a.antispam").mouseover(ontRot);