PHP: image link- rel or site?

Question

When it comes to php, I'm a newb.  I don't know much about writing the code. Here's my issue: I'm having problems with displaying an image in my right column (rightcol.php).
The image is viewable when you go to
http://www.spartanburgfamilydentistry.com/test/spartanburg_dental_patient_forms/
But not when you are on the main page:
http://www.spartanburgfamilydentistry.com/test/index.php
I've tried to link the image via REL and SITE, and I've linked the rightcol.php REL and SITE.
Can someone point me in the right direction? Any help is greatly appreciated!
<div id="pagewidth" >
  <!--insert header here-->
  <?php require_once('header.php'); ?>
<div id="contentwrapper">
   <div id="maincol">
       <img src="images/spartanburg_family_dentistry_front_office.jpg" alt="Dental Services Spartanburg SC" width="300" height="300" class="imageleft" />
     <br />
     <br />
     <h1>Welcome to Spartanburg Family Dentistry!</h1>
     <p>We are located just a few blocks from downtown Spartanburg, just across the street from the YMCA. We provide all types of dental services to meet your needs. We invite you to set up an appointment by clicking the button to the right or calling the number below. </p>
     <p>Call us at [phone] to speak with one of our friendly office staff and<strong> discuss your dental needs</strong>. We look forward to exceeding your expectations!</p>
    </div>
    <div id="rightcol" >
      <?php require_once('rightcol.php'); ?>
      <br />
    </div>
  </div>
      <div id="footer" >Spartanburg skyline picture courtesy of Glen Woodfin.</div>
  <!--insert footer here-->
  </div>
<?php require_once('footer.php'); ?>

Answer 1

Here's rightcol.php:
<div id="officehrs">
      <table width="210" border="0" cellspacing="0" cellpadding="1">
            <tr>
              <td colspan="2" align="left" bgcolor="#006633"><h5>Office Hours</h5></td>
             </tr>
            <tr>
              <td width="105" align="left">Monday</td>
              <td width="101" align="left">8:30am-5:30pm</td>
               </tr>
            <tr>
              <td width="105" align="left">Tuesday</td>
              <td width="101" align="left">8:30am-5:30pm</td>
               </tr>
            <tr>
              <td width="105" align="left">Wednesday</td>
              <td width="101" align="left">8:30am-5:30pm</td>
               </tr>
            <tr>
              <td width="105" align="left">Thursday</td>
              <td width="101" align="left">8:30am-5:30pm</td>
               </tr>
            <tr>
              <td width="105" align="left">Friday</td>
              <td width="101" align="left">Closed</td>
               </tr>
            <tr>
              <td colspan="2" align="left">Closed for lunch 12:30-1:30pm                
                 <hr size="1" noshade="noshade" /></td>
               </tr>
            <tr>
              <td colspan="2" align="left" bgcolor="#CC6600"><h5>Request Appointment</h5></td>
            </tr>
            <tr>
              <td colspan="2" align="left">Click <a href="#">here</a> to schedule an appointment!</td>
            </tr>
            <tr>
              <td colspan="2" align="left"><hr size="1" noshade="noshade" /></td>
            </tr>
            <tr>
              <td colspan="2" align="left" bgcolor="#FF66CC"><h5>Website Coupon</h5></td>
            </tr>
            <tr>
              <td colspan="2" align="left"><img src="../images/zoom_discount.jpg" alt="Zoom Teeth Whitening Discount" width="199" height="142" /></td>
            </tr>
             </table>
        </div>