Display Custom Fields on a list

Hi everyone, I have in several posts a custom field (promoimage) with value: “a path to an image”.
On my blog index I want to show all my posts with that custom field as images.

Here’s the code I got:

<div id="slider">
        <ul id="sliderContent">

            <li class="sliderImage">
                        <img src="<strong>??????</strong>" />
                <span class="top"><strong>Title text 1</strong><br />Content text 1...</span>
            </li>
             <div class="clearall sliderImage"> </div>
        </ul>
</div>

thanks and wait for your help.