Ajax response creating problem

Hello,
I am using ajax function for retrieving values from database. But in the response an extra blank line( \n ) comes. Here is my javascript which calls ajax.

var response = callInquiryAJAX('<?=base_url()?>inquiry/checkInquiry/inquiryHistoryId/'+recordIdStr1);

Code (markup):

And here is my ajax function which is called in order to retrieve data from php.

function callInquiryAJAX(url) 
{
      try 
      {
        req = new XMLHttpRequest(); /* e.g. Firefox */
      } 
      catch(e) 
      {
          try 
          {
              req = new ActiveXObject("Msxml2.XMLHTTP");
   /* some versions IE */
          } 
          catch (e)
          {
              try 
              {
                  req = new ActiveXObject("Microsoft.XMLHTTP");
  /* some versions IE */
              } 
              catch (E) 
              {
                 req = false;
              }
          }
     }

//      req.onreadystatechange = function() {responseInquiryAJAX(pageElement);};
       req.open("GET",url,false);
      
      
      req.send(null);
      if(req.readyState == 4) 
      {
         if(req.status == 200) 
         {
                  return req.responseText;
         }
      }
}

Code (markup):

I am unable to trace why it is giving such kind of output. I have checked PHP code as well as javascript code. There is nothing that is creating extra line. Please help me. Thanks in advance.