title: how to add a javascript alert with a PHP script?
body: <p>let's say i have an input form, wherein, it's use for an email address. this form is part of a long form so i use an alert box instead when other inputs got errors....my question now is, if I checked the email input string via php, if it has been taken , how will I put the message like e.g "this email has been taken" in an alert box if i am using PHP to check it from backend ?..i want an alert box, since I use it with the other input boxes that don't need a backend check
  e.g</p>
  
  <pre><code>alert("$errormessage");
  </code></pre>