like for example

I click this link
this automatically submits "test" to google

how can I make a link that automatically submits "test" to my script?
the script may need to be adjusted to allow this, and I am not sure what I need in my url to actually make it work.

here is the code to the script
        // Check if the user submitted this form
        if (isset($_POST["submitwrite"])) {
 echo $_POST['usersname'];
                // Open the file in write mode
                $handle = fopen("writetest.txt","a+"); 
                // If successful
                if ($handle) {
                        // Write to that handle the username submitted in the form and the date
                        fwrite($handle,$_POST["usersname"] . " - " . date("Y-m-d"));
                        // Close the file

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"

<html xmlns="" lang="en" xml:lang = "en" dir="ltr">
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>Submit example</title>

<!-- Notice how the form is submitting to itself -->

<form method="POST" action="test.php" name="form1" id="form1">
Name: <input type="text" name="usersname"/><br/>
<input type="submit" value="Write" name="submitwrite"/>