Debuging Error Problem

[eluser]h54yo[/eluser]

Code:

$this->_pageAuth();
            //add validation
            $rules['textRequestNo'] = "required|alpha_numeric;
            $rules['textRequestor'] = "required|numeric";

the error in line

$rules['textRequestNo'] = "required|alpha_numeric;

because there is no closing double quotes, but CI can not show that error, so I have to search the code line by line it's killing me