title: MongoDB + Node.js RegEx find() not working
body: <p>I want to find everything in a database which contains a specific word. So I decided to use RegEx. But it's not working with a variable. If I use regex without any variables, it works completely perfect. An example for that:</p>
  
  <pre><code>app.post("/test", function(req, res){
  let tagcontent = req.body.q.tag;
  let regexValue = '/'+tagcontent+'/';
  
    Tags.find({"tagname": /exampletag/}, function(err, tags){
  
      if(err){
        console.log(err);
      }else{
        res.send(tags);
      }
  
    });
  });
  </code></pre>
  
  <p>But when I'm trying to use this query with a variable, MongoDB shows me an empty result. Example:</p>
  
  <pre><code>app.post("/test", function(req, res){
  let tagcontent = req.body.q.tag;
  let regexValue = '/'+tagcontent+'/';
  
    Tags.find({"tagname": new RegExp(regexValue)}, function(err, tags){
  
     if(err){
       console.log(err);
     }else{
       res.send(tags);
     }
  
    });
  });
  </code></pre>
  
  <p>What can i do? Thanks for any help.</p>