private void updateGlunStatus() {
        String text = this.glGlun.getText();
        String allowedCharacters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/_-";
        if(text.length() == 0) {
            this.glGlunStatus.setText("<html>Enter your GL_GLUN. It is <b>case sensitive.</b></html>");
        } else if(text.length() < 24) {
            this.glGlunStatus.setText("<html>Too short! Needs to be 24 characters long.</html>");
        } else if(text.length() > 24) {
            this.glGlunStatus.setText("<html>Too long! Needs to be 24 characters long. Only enter the part inbetween the &lt;string&gt; and &lt;/string&gt; tags.</html>");
        } else if(!text.matches("["+allowedCharacters+"]+==")) {
            this.glGlunStatus.setText("<html>Invalid characters. Only 'A-Z', 'a-z', '0-9', '+', '/', '_' and '-' followed by '==' are allowed.</html>");
        } else {
            this.glGlunStatus.setText("<html>Looks like a valid GL_GLUN. :)</html>");
        }
    }