How to combine contents two text boxes into one text box

Thanks in advance for your help, as I am a novice user. In Adobe Acrobat 7, am trying to create a form that autopopulates text boxes in several pages. For example, first name will populate on all text boxes named "first name". I am wondering if there's a way to combine the contents of two text boxes into one box. For instance, can I have text box called "first name" plus text box called "last name" to autopopluate the text box called "full name"? I know this question is probably pretty simple, so thanks for walking me through it.