Help with wp_dropdown_categories – Pre Selected Values in Multi-Select

I have been staring at the following block of code for while now and could use a little help. It is part of of a modified user profile. When the user is editing the values via a form the multi-select form element should be pre-populated with the values contained with in the user’s profile. I just can’t seem to get the selected=”selected” attribute added to those options. Any help would be greatly appreciated!!

job_ind_pref_call = custom user field

<?php
				$sel = 0;
				$sel1 = get_user_meta($user_ID, 'job_ind_pref_call', true);
				if(isset($_POST['job_ind_pref_call'])) {

					$sel1 = $_POST['job_ind_pref_call'];
				}
				if (isset($posted['job_term_cat']) && $posted['job_term_cat']>0) $sel = $posted['job_term_cat'];
				global $featured_job_cat_id;
				$args = array(
				    'orderby'            => 'name',
				    'exclude'			 => 3,
				    'order'              => 'ASC',
				    'name'               => 'job_ind_pref_call[]',
				    'hierarchical'       => 1,
				    'echo'				 => 0,
				    'class'              => 'job_cat',
				    'selected'			 => $sel1,
				    'taxonomy'			 => 'job_cat',
				    'hide_empty'		 => false
				);
				$dropdown = wp_dropdown_categories( $args );
				$dropdown = str_replace('class=\'job_cat\' >','class=\'job_cat\' multiple="multiple" size="6" onClick=GetMDDselections("job_ind_pref_call") ><option value="">'.__('Select a Line&hellip;', 'colabsthemes').'</option>');
				echo $dropdown;
			?></p>