I have the following structure:

|-HolderPage
|---Page 1
|---Page 2

where Page 1 & 2 are children of the HolderPage. In my case, my Pages have a "has_many" relation to ImageResources (Images with Title and Caption). Now I'd like to automatically generate a list of the children within my HolderPage (that works really well) and add one (the first) of the ImageResources as a thumbnail to the list-entries on my HolderPage. I tried

function getOneHiglightImage() {
   	return $this->HighlightImages("", "SortOrder ASC", null, 1);
}

within Page.php. For the template of the HolderPage I'm using:

function getChildren() {
  		return DataObject::get("Page", "ParentID = $this->ID", "Title ASC", "", "" );
	}

and

<ul id="List">
    			<% control getChildren %>
      				<li>
  					   	<div class="Photo">
  					   	        $getOneHiglightImage.HighlightAttachment  					   		
  					   	</div>
   					   	<div class="Title">
   					   		<% control Type %>
   					   			<a href="$Link" title="$Title">$Title</a> 
   					   		<% end_control %>
   					   		<a href="$Link" title="$Title">"$Title"</a></div>
   						<div class="Summary">$Content.FirstParagraph</div>
    					<div class="ReadOn clearfix">
    						<a href="$Link" title="$Title"><% _t('READMORE','Read more') %> ...</a>
    					</div>
    				</li>
    			<% end_control %>
  			</ul>

HighlightAttachment is where the Image is stored. But that doesn't work for me. Can someone help me?

Why can't you just use $HighlightImages.First?

Because I didn't know that it works that easy ;). Thank you.