I have an html form used to edit a record in a mysql table.
In the case of editing, I prefill the form with the current values for the record as returned by the query, as below:

<INPUT TYPE="text" NAME="SITENAME" SIZE=35 VALUE="<?php echo $customer['sitename']; ?>">

I would like to use the same form for creating a new record, but of course there would be no values assigned to the sql query array, and as such the form would not work.
I know I could put an IF or ISSET for every input, or a single one but then have to duplicate the form code without each echo statement. Both seem cumbersome.

Is there a better way to use the same form code?