jquery可视化网站优化器代码

var _vwo_code=(function(){
var account_id=7237,setTings_tolerance=2000,library_tolerance=1500,use_exisTing_jquery=true,// DO NOT EDIT BELOW THIS LINE
f=false,d=document;return{use_exisTing_jquery:function(){return use_exisTing_jquery;},library_tolerance:function(){return library_tolerance;},finish:function(){if(!f){f=true;var a=d.getElementById('_vis_opt_path_hides');if(a)a.parentNode.removeChild(a);}},finished:function(){return f;},load:function(a){var b=d.createElement('script');b.src=a;b.type='text/javascript';b.innerText;b.onerror=function(){_vwo_code.finish();};d.getElementsByTagName('head')[0].appendChild(b);},init:function(){setTings_timer=setTimeout('_vwo_code.finish()',setTings_tolerancE);this.load('//dev.visualwebsiteoptimizer.com/j.PHP?a='+account_id+'&u='+encodeURIComponent(d.URL)+'&r='+Math.random());var a=d.createElement('style'),b='body{opacity:0 !important;filter:alpha(opacity=0) !important;BACkground:none !important;}',h=d.getElementsByTagName('head')[0];a.setAttribute('id','_vis_opt_path_hides');a.setAttribute('type','text/css');if(a.styleSheet)a.styleSheet.cssText=b;else a.appendChild(d.createTextNode(b));h.appendChild(a);return setTings_timer;}};}());_vwo_setTings_timer=_vwo_code.init();

但我想只在这种情况下运行此代码：

$(document).ready(function(){
  if($('#SELEctedLang').val() == 'en_US')
  {
    //run the visual website optimizer code
  }
});

我试过这个,但返回错误“_vwo_code未定义”

$(document).ready(function(){
  if($('#SELEctedLang').val() == 'en_US')
  {
    var _vwo_code=(function(){
    var account_id=7237,// DO NOT EDIT BELOW THIS LINE
    f=false,'text/css');if(a.styleSheet)a.styleSheet.cssText=b;else a.appendChild(d.createTextNode(b));h.appendChild(a);return setTings_timer;}};}());_vwo_setTings_timer=_vwo_code.init();
  }
});

请帮我解决这个问题？提前致谢！