I want to send only one variable via the post method. I have queried the database and have to post $row[id] variable to the page along with the form. To send the user's input we simply do dfs. and the value is send. But, how can i send the variable $row[id] to the file. And also, how would I access it?
Not sure if I understand your question correct, but you could try to use hidden input to store your variable:
<input type="hidden" name="whatever_name" value="whatever_value" />
You can access it on PHP side the same as any other