Custom url redirect the page say You do not have sufficient permissions to access this page

i have an error message whe i tring to set the page in custom url can anybody to tell that any action or hook to set the page or function. here is my code

 <a href='<?php echo admin_url("admin.php?page=wp_crm_asign&user_id={$user_id}"); ?>'>Asign to Consultant</a>

add_action( 'admin_init', 'wp_crm_asign_admin_init' );

 function wp_crm_asign_admin_init() {

   if ($_GET['page'] == 'wp_crm_asign') {

    echo "hello";
   //set my action

    }
   }

Can Anybody to tell the right way to do this. thanks

via Chebli Mohamed