show alert code example

Example 1: show alert in php

echo '<script language="javascript">alert("juas");</script>';

Example 2: javascript alert

alert("string");

Example 3: input show validation message

// Validate emai

var applicationForm = document.getElementById("applicationForm");    
if (applicationForm.checkValidity()) {
  applicationForm.submit();
} else {
  applicationForm.reportValidity();
}