I’m trying to capitalize the first character of a string from user input field. Below is the listener tag that collects the firstname data.

`<script>
(function () {
  var element = document.querySelector('input[name="firstname"]') 

  element.addEventListener("blur", function(e) {
  dataLayer.push({
                    'event': 'first_name', 
                    'first_name': e.target.value                   
              });
  }, true);
})();  
    </script>`

I’ve tried a few variations of the below but none are working

`<script>
(function () {
  var element = document.querySelector('input[name="firstname"]'); 
  **var elementUpper = element.charAt(0).toUpperCase() + str.slice(1);**

  **elementUpper**.addEventListener("blur", function(e) {
  dataLayer.push({
                    'event': 'first_name', 
                    'first_name': e.target.value                   
              });
  }, true);
})();  
</script>`

I’ve also created a new tag with the below HTML which isn’t working.

`function() {
  var txt = {{dlv - first_name}};
  return txt.replace(/wS*/g, function(t){
    return t.charAt(0).toUpperCase() + t.substr(1).toLowerCase();
  });
}`

Any guidance would be appreciated.