Just type the letters that you see in the image below the text field. You don't have to match the case: you can type "e" for both "E" and "e".
If you can't read the text, click the refresh icon below the image (double arrow). That will load a new image.
These kind of login images (called Captcha tests) are commonly used on websites to verify that the login is being submitted by a person.
It's become necessary to do this check, because of special scripts and programs that automatically submit forms (sometimes used to send spam). This makes the RLID application less available for legitimate users of the system and slows down the application unnecessarily.
A CAPTCHA is a challenge response test used on computers to check if the user is human. A common kind of CAPTCHA that is used on websites requires that the visitor type the letters and numbers of a distorted image. This method is based on the fact that is difficult for computers to extract the text from the image while it is very easy for humans.