Create Recurring Payment profile failed

Hi All I am implementing recurring payments with paypal. My paypal script is already running now embedding recurring payments in it. I have searched a lot and not find any useful material. I found from Recurring some material. I implemnted the code of createrecurringpaymen开发者_JAVA百科ts.php from here and changed the variables accorinding to mine. I redirect browser to this file from DoExpressCheckoutPayment.php when transaction is completed. But at createrecurringpayment.php I always get the following error.CreateRecurringPaymentsProfile failed: Array ( [TIMESTAMP] => 2011%2d03%2d28T11%3a44%3a30Z [CORRELATIONID] => 81d0c488123c4 [ACK] => Failure [VERSION] => 54%2e0 [BUILD] => 1776465 [L_ERRORCODE0] => 10002 [L_SHORTMESSAGE0] => Security%20error [L_LONGMESSAGE0] => Security%20header%20is%20not%20valid [L_SEVERITYCODE0] => Error ).

there may be below 4 causes for this type of error you found..

1. You have your PayPal module configured to "Sandbox" but have not used Sandbox API credentials.

2. You have your PayPal module configured to "Live" but have not used Live API credentials.

3. You have mis-typed one or more API credentials entries, including but not limited to leaving trailing spaces.

4. You have deleted and/or recreated new API credentials in your PayPal account but have not copied those new credentials back to your store.

Just check it out..it may helpful to you..

Thanks.

I have found the solution.... I was using paypal Express Checkout.. With this it is not possible to implement recurring payments...