jquery - How do I have a different image load on each page refresh? -

I am trying to load a different image with each page refresh. I have tried this code:

    
 But I'm a jQuery and JavaScript Newbill, and it's not working for me. I'm definitely doing something wrong, but I do not know where to start with jQuery. I'm pretty sure this is a syntax error. Can someone help me?  
 Thank you!   
 
 
 Something is back and forth, but here's the code, should not cause any problems:  
  
 
 Your code works  
 If you still have problems, try loading jQuery. The browser may complain that the anonymous function is created outside the first match of the bracket:  
 incorrect:  
 }) (jQuery);   
 Correct:  
 } (jQuery));