Submitting client reviews

I generally encounter a lot of if/else. I would like to get some suggestions on my code:

if( $blnLogged && isset( $_POST['postReview'] ) )
{
    if( $_SESSION['REVIEW']['SUBMITTED'] != '' )
    {
        $arrSharedData['blnRetSave'] = $_SESSION['REVIEW']['SUBMITTED'];
        $blnShowForm = false;
        $blnReviewPosted = true;
    }else{
        if( $arrData['captcha'] != $_SESSION['REVIEW']['CODE'] )
        {
            $strErrMsg = 'Invalid Captcha Code...';
        }else{
            if( empty( $arrData['review_title'] ) || empty( $arrData[ 'review_description' ] ) || empty( $arrData[ 'overall_review' ] ) || empty( $arrData[ 'cleanliness' ] ) || empty( $arrData[ 'facilities' ] ) || empty( $arrData[ 'location' ] ) || empty( $arrData[ 'quality_of_service' ] ) || empty( $arrData[ 'room' ] ) || empty( $arrData[ 'value_of_money' ]) )
            {
                $strErrMsg = 'Required field missing...';
            }else{

                //do we need any processing...
                $arrData['business_id'] = $bID;
                $arrData['client_id']   = $_SESSION['site_user'];
                $arrData['website_id']  = WEBSITE_ID;
                $arrData['review_date'] = date('Y-m-d');

                //If field Transformation required do it...

                $objTripReview = SM_Loader::loadClass('Class_Reviews');
                $blnRetSave = $objTripReview->saveReview( $arrData );
                $_SESSION['REVIEW']['SUBMITTED'] = $blnRetSave;
                $arrSharedData['blnRetSave'] = $_SESSION['REVIEW']['SUBMITTED'];
                $blnShowForm = false;
                $blnReviewPosted = true;
            }
        }
    }
}

if( $blnShowForm === true )
{
    $_SESSION['REVIEW']['CODE'] = rand(9999,99999);
    $_SESSION['Review']['SUBMITTED'] = '';
}

One simple way to improve this is to package it in a function, and return (or throw an exception) after each $strErrMsg = ... line. This will flatten the function, and allow you to put the main functionality at the "top level" of the function.

Even better might be to move all the validation code to a separate function that throws an exception, and then handle it in the function that called it with the wrong parameters.

StackExchange Code Review Q#985, answer score: 6