Connecting a 2nd monitor

I'm trying to connect a 2nd monitor to my desktop and I don't know how to go about doing it. The cable for the monitor is a 15 pin male VGA I believe. I have pictures of the monitor cable and the back of the desktop, but since I'm a new user I can't post them.

Any help would be greatly appreciated. Thanks!

You can not use a simple double headed cable.
It will not work and will likely destroy the
monitors, graphics card, possibly even the mobo.
It does require electronic components.
I've never seen what you describe
in just a cable assembly.

But you can achieve your goal...
Check out the website of aten
click on 'Video Splitters' at the low right corner.
On that new page... view the selections...
- or - use the 'key word search' box
- or - use the 'drop down list'
to locate and view the below products
VS82
VS132A
VS182
VS0202
There are likely others.

Please do read the descriptions carefully.
Spec sheets are there.
Distance may be a consideration as
cable length/quality may become an issue.
Audio (if desired) may be a consideration.
Using CAT5 is possible.
Budget/cost may be a consideration.
Finding it is another issue.
These use to be called 'Console Sharing Device'.
Now seems 'Video Splitter' in vogue.
Regardless, it is not a 'Video Switch'.

For you to use two monitors, both must be able to physically connect to your computer....To add a second monitor to your computer, you'll need to make sure that you either have a video card that supports multiple monitors, or that your computer has more than one video card.