Little problem with a form

Hi to all: I don't have a lot of experience with php. I do some examples with php to receive the data for a form and generate an e-mail. I want to receive the data and i want to separate the name of the diferents data fields of the form and the data of it. I do an example: <form ......> <input name="first[1]" ......> <input name="first[2]" ......> <input name="first[3]" ......> </form ....> And i can get the value of the diferents fields. But i want to obtain the name of the diferents fields to. Because i wanto to generate an e-mail like this: Information receive from the web : Name : Juan Pérez Address : Ribera street. City : Pamplona ...... Someone can help me. Or tell me where i can find a similar example. Thanks. Best regards, Diego.