frames.php
public function getTransportError()
    {
        if (is_integer($this->focus)) {
            return $this->frames[$this->focus]->getTransportError();
        }

        return $this->frameset->getTransportError();
    }
public function getTransportError()
    {
        if (is_integer($this->focus)) {
            return $this->frames[$this->focus]->getTransportError();
        }

        return $this->frameset->getTransportError();
    }
Accessor for last error.

@return string        Error from last response.