Wp_Custom Field use

        <!--Custom post default -->

        <?php $your_variable= get_post_meta($post->ID, 'your_custom_field_id', true); ?>


        <!-- use -->
        <?php echo $your_variable; ?>


        <!-- Custom post if exists -->

        <?php if($your_variable) :  ?>
                <a href="<?php echo $your_variable; ?>" class="job_pdf">Download Instructions</a>
        <?php endif; ?>



       <!-- Custom post dynamic -->

        <?php if ( $your_variable ) : ?>
                <a href="<?php echo $your_variable; ?>" class="job_pdf">Download Instructions</a>
        <?php else : ?>
                <p style="float:right">no job instructions available</p>
        <?php endif; ?>


        <!-- use Custom  Field in idex.php -->
        <div class="slider">

    <?php
    // Determine context
$page_id = ( 'page' == get_option( 'show_on_front' ) ? get_option( 'page_for_posts' ) : get_the_ID );

// Echo post meta for $page_id
$your_variable = get_post_meta($page_id, 'your_variable', true);
$your_variable = get_post_meta($page_id, 'your_variable', true);

 ?>

        <h2><?php echo $your_variable; ?></h2>
        <h3><?php echo $your_variable; ?></h3>
    </div>