<html>
    <body>
        <form action="4-7.php" method="get">
            :
            <input type="text" name="userName" size="12">
            :
            <input type="text" name="pass" size="12">
            <input type="submit" value="">
        </form>
    </body>
</html> the very simple web page above, open 
 127.0.0.1 move 4-7.php 
  
 
A drop-down box appears when the mouse clicks on the user name. Excuse me, how did the data in this drop-down box come from?
