A PHP Error was encountered (Missing argument 1)

[eluser]glenconde[/eluser]
good day igniters,

please help a little bit here..
i got this problem:

A PHP Error was encountered
Severity: Warning
Message: Missing argument 1 for Sale_lib::insufficient_stock(), called in C:\xampp\htdocs\elcon\application\controllers\sales.php on line 245 and defined
Filename: libraries/Sale_lib.php
Line Number: 289

A PHP Error was encountered
Severity: Notice
Message: Undefined variable: item_id
Filename: libraries/Sale_lib.php
Line Number: 292

A PHP Error was encountered
Severity: Notice
Message: Undefined variable: item_id
Filename: libraries/Sale_lib.php
Line Number: 295

this is my code:

controllers/sales.php

Code:

245    if (!$this->sale_lib->insufficient_stock() == True)
246  {
247   $data['error'] = $this->lang->line('sales_insufficient_stock');
248   $this->_reload($data);
249   return false;
250  }

libraries/Sale_lib.php

Code:

289    function insufficient_stock($item_id)
290 {
291  //make sure item exists
292  if(!$this->CI->Item->exists($item_id))
293  {
294   //try to get item id given an item_number
295   $item_id = $this->CI->Item->get_item_id($item_id);
296
297     if(!$item_id)
    return false;
     }
  
         $item = $this->CI->Item->get_info($item_id);
      $quanity_added = $this->get_quantity_already_added($item_id);
      
     if ($quanity_added > $item->quantity)
    {
     return true;
    }
  
    return false;
}

PLEASE HELP WHAT AM I MISSING??
Thank you in advance..

[eluser]InsiteFX[/eluser]
It is expecting the $item_id to pass into it!

You could intialize it!

Code:

function insufficient_stock($item_id = NULL)