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();
}