PHP and Javascript error

I am trying to do something like this.

<script type="text/javascript">
 $(wi开发者_StackOverflowndow).load(function(){
    <?php
        if(isset($_SESSION['tagname']))
    {
    ?>
        var t = <?php echo $_SESSION['tagname'] ?>;
        $('.tag span').html(t);
    <?php
    }
    else
    {
    ?>
    $('.tag').hide();
    <?php
    }
    ?>
});
</script>

Now the problem is, the variable 't' is not getting set. If I write a static text inside that line of code, then my code works.

Is there anything I am doing wrong here?

If t is a string value, then that should be a syntax error because you would be using a string outside quotes.

Try

var t = '<?php echo $_SESSION['tagname'] ?>';

Encode as JSON before outputting text to be used as JavaScript literals.

var t = <?php echo json_encode($_SESSION['tagname']) ?>;

And of course, make sure that $_SESSION['tagname'] actually contains something.

Because the t variable contains a string, which should be enclosed in single or double quotes (in this case, double quotes, as you have single quotes inside the string so it doesn't mess up).

var t = "<?php echo $_SESSION['tagname'] ?>;";

And, it depends if "tagname" is a Javascript variable or not.