Cannot get line guides to show up.

[Adkins77]

I cannot get the line guides to pop up, so that I can center a clip in the frame. I used to use this function and now when I click on the icon, nothing happens. I cannot get it to come up. I have attached a photo of my workspace and circled the button I'm talking about so that you know which button I'm talking about. 

I am not as savvy as some people and I know this is probably some menu setting that I changed somehow inadvertently, but the interface system is far too complicated and changes far too easily in my opinion. 

Anyway, thanks in advance for the help.

[Ann Bens]

You need to have them drawn first

Open the ruler as well.