Disable convert lead

view.detail.php

<?php
//custom/modules/Leads/views/view.detail.php
if(!defined('sugarEntry') || !sugarEntry) die('Not A Valid Entry Point');

require_once('include/MVC/View/views/view.detail.php');

class CustomLeadsViewDetail extends ViewDetail
{

    function display()
    {
        global $sugar_config;

        //If the convert lead action has been disabled for already converted leads, disable the action link.
        $disableConvert = ($this->bean->status == 'Converted' && !empty($sugar_config['disable_convert_lead'])) ? TRUE : FALSE;

        $disableConvert = true; //wrap additional logic around this
        $this->ss->assign("DISABLE_CONVERT_ACTION", $disableConvert);
        parent::display();
    }
}