Here are some quick rules to follow when writing dialogue. First, remember to use quotation marks in order to highlight words that are being spoken by characters. Next, you should remember to always start a new paragraph when changing speakers. When you use this method you wont need a speech tag such as "said John" in your written dialogue. You must make it clear to the reader who is speaking
. and always use correct punctuation, capitalization and spacing. You can find more information here: http://mrbraiman.home.att.net/page13.html