in the validation, you have set the like entry use the captcha_Security_Code_1 Session variable for both the initial server variable and the comparison,
$WAFV_Errors .= WAValidateLE(strtolower($_SESSION['captcha_Security_Code_1']) . "",strtolower($_SESSION['captcha_Security_Code_1']) . "",true,1);
instead, you need to select the Security_Code_1 form element, and compare that to the captcha_Security_Code_1 session:
$WAFV_Errors .= WAValidateLE(strtolower($_POST['Security_Code_1']) . "",strtolower($_SESSION['captcha_Security_Code_1']) . "",true,1);