[![enter image description here](https://i.stack.imgur.com/UniMo.png)](https://i.stack.imgur.com/UniMo.png)I am currently trying to insert some text in a specific spot at a website, <http://kawowii.com> , however, I keep getting error messages. These error messages seem to originate from the section I am trying to select using javascript (variables txtClasses and styleClasses). The error messages are 

> 
> Uncaught TypeError: Cannot set property 'textContent' of undefined
> 
> 
> 

So, the variables seem to be undefined but I don't understand why. I have looked at the other answers and still cannot determine what is wrong. 

Right now, I have

```
window.onload = function() {
    var txtClasses = document.querySelectorAll("div.coord-control.leaflet-control");
    txtClasses[0].textContent = "Server: UP Location:"
}

```

and I tried this

```
window.onload = function() {
    var styleClasses = document.querySelectorAll(".coord-control leaflet-control");
    function insertAfter1(referenceNode, newNode) {
        referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);
    }
    var brk = document.createElement("br");
    insertAfter1(styleClasses[0], brk);
    var div = document.createElement("div");
    var textNode = document.createTextNode("Server: UP")
    div.appendChild(textNode);
    insertAfter1(brk, div);
}

```

My end goal is to change the website, kawowii.com , such that before `Location :`, it reads `Server: UP` using javascript.