title: alphanumeric regex javascript
body: <p>I am having a problem to get the simple reges for alphanumeric chars only work in javascript :</p>
  
  <pre><code>var validateCustomArea = function () {
          cString = customArea.val();
          var patt=/[0-9a-zA-Z]/;
          if(patt.test(cString)){
              console.log("valid");
          }else{
              console.log("invalid");
          }
      }
  </code></pre>
  
  <p>I am checking the text field value after keyup events from jquery but the results are not expected, I only want alphanumeric charachters to be in the string</p>