Navigation menu advice needed

Very much a novice with PHP.

I’ve written a bit of code to generate the html for a horizontal nav menu with drop downs.

What I have works, but i’m sure it’s over engineered and badly written.

Any advice would be greatly appreciated.

This is the code

  <ul id = 'nav'>
<?php

  $currPage = basename($_SERVER['SCRIPT_FILENAME'], '.php');

  $pages = array( 'index', 
                  'gallery' => array(
				    'critters',
					'product viz',
					'architecture',
					'characters',
					'misc'
				  ), 
				  'profile' => array(
				    'test1',
				    'test2'
				  ), 
				  'contact', 
				  'tutorials', 
				  'links'
				);
  
  foreach ($pages as $parentMenu => $page){
	
	echo("    <li>");
	
	// If no submenu (Not array)
	if (!is_array($page)) {
	
	  echo( "<a href='$page.php'"
	    . ( ($page === $currPage) ? " class = 'active'>" : '>' )
	    . ( ($page === 'index') ? 'home' : $page )
	    . "</a>");
	  
	// Submenu
	} else {
	
	  // Using a for loop as I need to add a class to the last index
	  $arrLen = count($page);

	  echo( "<a href='$parentMenu.php'"
	    . ( ($parentMenu === $currPage) ? " class = 'active'>" : '>' )
	    . "$parentMenu</a>\
      <ul>\
" );
	  
	  for ($i = 0; $i < $arrLen; $i++) {
	  
	    echo("        <li>" 
		  . "<a href='$parentMenu.php?catID=" . ($i+1)
		  . ( ($i === $arrLen-1) ? "' class = 'last'>" : "'>" )
		  . "$page[$i]</a></li>\
" );

	  }
	  echo ("      </ul>\
    ");
	
	}
	
	echo ("</li>\
");
    
  }
  
?>
  </ul>

and the output


  <ul id = 'nav'>
    <li><a href='index.php' class = 'active'>home</a></li>

    <li><a href='gallery.php'>gallery</a>
      <ul>
        <li><a href='gallery.php?catID=1'>critters</a></li>
        <li><a href='gallery.php?catID=2'>product viz</a></li>
        <li><a href='gallery.php?catID=3'>architecture</a></li>
        <li><a href='gallery.php?catID=4'>characters</a></li>
        <li><a href='gallery.php?catID=5' class = 'last'>misc</a></li>
      </ul>
    </li>
    <li><a href='profile.php'>profile</a>
      <ul>
        <li><a href='profile.php?catID=1'>test1</a></li>
        <li><a href='profile.php?catID=2' class = 'last'>test2</a></li>
      </ul>
    </li>
    <li><a href='contact.php'>contact</a></li>
    <li><a href='tutorials.php'>tutorials</a></li>
    <li><a href='links.php'>links</a></li>
  </ul>

Thanks ahead.

RLM