javascript不处理php变量

for some reason its not processing-- var user = variable, when i view the results-- mysite.com/image_upload/uploads/';/

  (function($){
     $.simpleuploader = {version: '0.1'};
     $.fn.simpleuploader = function(options){
    // the container to inject the form into
    var $this = $(this);


    var user = '<?php echo json_encode($uid); ?>';

    // set defults
    var defaults = {
        prefix: 'simpleuploader-',
        latency: 500,
        reuse: true,
        when: 'onchange',
        submitText: 'Submit',
        disabledOpacity: .3,
        settings: {
            fullPath: 'http://www.mysite.com/image_upload/uploads/' + user + '/',
            relPath: '../uploads/' + user + '/',
            maxSize: '4194304',
            maxW: 300,
            maxH: 300,
            colorR: 255,
            colorG: 255,
            colorB: 255
        },

json_encode() produces a javascript object, and that does not belong inside quotes. There is probably a quote or something in your echo statement that is messing up the javascript. Try changing that line to this.

var user = <?php echo json_encode($uid); ?>;

That being said, json_encode() on a single variable is bad practice, and a weird way to do something. If the $uid is just a number, why not use:

var user = <?php echo $uid; ?>;