form submit

form submit

hi, a have a php script that doesn't execute or something. I hope you can help.
Now the whole page is reloaded and i don't get the "data loaded" alert. The page should not be reloaded after a submit and i would like to know if I can call a script via jquery

The javascript. Placed in the <head> section. The alert works.
      $("form#testForm").submit(function()
      {      
         //alert("begin testform ");
         $.post("scripts/test.php", function(data){
            alert("Data Loaded: " + data);
         });
      });


The php script. I didn't know if I have to echo or return for seeing the data in the alert of the $.post ()
<?php
echo "echo";
return "return";
?>


my HTML form
<form id="testForm">   
   <input type="text" id="test" />                        
<input type="submit" value="save"/>
</form>