Why is alert in microAjax not outputting text echoed from php file?
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I am trying to get a string from a text file. I have a php file called genjsonGPS.php that looks like this:

    <?php

    $myFile = "vesselGPS.txt";
    $fh = fopen($myFile, 'r');
    $vesselGPS = fread($fh, filesize($myFile));
    fclose($fh);

    echo("Hello");


    ?>

When I run it, I get for an output in my browser:

"Hello"

I have a webpage with a js file using microAjax (from the js file):


    microAjax("genjsonGPS.php", function (res) {
      alert (res);
    });


When I run the webpage I get a blank alert. When I change the function above to: 

    microAjax("genjsonGPS.php", function (res) {
      alert (res);
    });

I get an alert that says:
     function toString() { [native code] }




How do I get the function above to output "Hello" in the alert like the browser does?