reCAPTCHA not working help me

Hello all i m try to run recaptcha and register my domain and get api key butt i dont no how to fix every time its show me this erro ... To use reCAPTCHA you must get an API key from http://bit.ly/1vMXyeg is any one help me solve my problem .. i m post my full file code plz some one tell me whr i can add api key and how to fix this isshu Thanx advance for help me -- You received this message because you are subscribed to the Google Groups "reCAPTCHA" group. To unsubscribe from this group and stop receiving emails from it, send an email to recaptcha+unsubscribe@googlegroups.com. To post to this group, send email to recaptcha@googlegroups.com. Visit this group at http://bit.ly/1dkFnYd. For more options, visit http://bit.ly/P65DvS.