Getting the height of a
- returns 'undefined'

Question

I have a problem getting the height of a (the one in the code below, with class="post_div"). And I want to return with a document.write whitin the HTML body - maybe later using it as height for other elements, that I want to be equal. I have tried every possible code for getting the height of such an element, but every time it returns 'undefined'. I have also tried setting height=auto for the DIV. I am almost sure my problem not has to do with the way I get the height, but have no other idea for what else it could be! Therefore I have choosen to bother you with the full structure of my coding. The JavaScript is placed in a separate document containing only the following statement: ``` var result=document.getElementById('postHeight').offsetHeight; ``` My HTML document looks like this ``` ...

Accepted Answer

There is no element with the ID `postHeight`. Perhaps you meant

```
var result=document.getElementById('content').offsetHeight;
```

Additionally, this calculation must be done after the element you are calculating has been loaded (so either by putting the `<script>` after the element, or deferring execution with `onload` or similar).

Getting the height of a <DIV> - returns 'undefined'

Solution

Problem