I have the following ajax code:
<script type='text/javascript'>
$(document).ready(function () {
    $('.questionform').on('submit', function(e) {
        e.preventDefault();
        $.ajax({  
            url :  "aplaygroundajaxtest.php",
            type: "POST",
            data: $(this).serialize(),
            success: function (data) {     
 '<?php
if($data3["{$QuestionType}Percent"]<100){ ?>' alert("Alert Message OnClick"); '<?php ;} ?>'
            },
        });
    });
});
</script>
If the value in column {$QuestionType}Percent is less than 100, I want it to alert a message. However, it does not work. the source code shows the following:
<script type='text/javascript'>
$(document).ready(function () {
    $('.questionform').on('submit', function(e) {
        e.preventDefault();
        $.ajax({  
            url :  "aplaygroundajaxtest.php",
            type: "POST",
            data: $(this).serialize(),
            success: function (data) {     
 '' alert("Alert Message OnClick"); ''
            },
        });
    });
});
</script> 
I've tried escaping the " with \ and I've also tried double quotes around the php (in which case, the PHP still disappears in the source code, leaving empty double quotes). 
I know that the issue does not lie with $data3["{$QuestionType}Percent"]<100 as it functions correctly elsewhere in my code - and the value in the column is indeed less than 100.
EDIT / UPDATE ---------------------------------------------->
The issue was two-fold: 1) I needed to get rid of the single quotes around PHP tags; 2) it wasn't receiving the value of $data3["{$QuestionType}Percent correctly.  
In the URL to which the form posts (aplaygroundajaxtest.php), I corrected the latter issue; now, I'm using the variable $QuestionTypePercent. In the code below, print_r($QuestionTypePercent); shows 14 in the source and the if condition is correctly interpreted. The source shows 14 alert("Alert Message OnClick"); and I get the error Uncaught SyntaxError: Unexpected identifier. When I remove print_r($QuestionTypePercent); the error goes away and the code works. Why is print_r($QuestionTypePercent); interfering with my alert in the code below? 
<script type='text/javascript'>
$(document).ready(function () {
    $('.questionform').on('submit', function(e) {
        e.preventDefault();
        $.ajax({  
            url :  "aplaygroundajaxtest.php",
            type: "POST",
            data: $(this).serialize(),
            success: function (data) {        
  <?php
print_r($QuestionTypePercent); // RETURNS 14 CURRENTLY
          if($QuestionTypePercent < 100){?>
                alert("Alert Message OnClick"); //REDIRECTSME TO aplaygroundajaxtest.php
                <?php } ?>
            },
        });
    });
});
</script>
 
     
     
    