Can I pop up alert in javascript using php

Question

I want to trigger javascript alert using PHP. Is it possible

I want to use it in head section, for displaying it at load time.

Answer 1

Of course this is possible.

All you are doing is outputting JavaScript, it's all the same thing.

The only issue is that you are nesting <script> tags, which is an HTML error, so get rid of the tags in the echo string.

<script type="text/javascript">
<?php 
    $valid="valid";
    if(!isset($valid))
        echo "alert('Hi');";
?>
</script>

By the way, as i'm sure you already know, this specific code will ALWAYS echo the "alert('Hi');"