+ 2

Cannot read property 'addEventListener' of null

```HTML Code <form id="sizePicker"> Grid Height: <input type="number" id="inputHeight" name="height" min="1" value="1"> Grid Width: <input type="number" id="inputWidth" name="width" min="1" value="1"> <input type="submit" id="submit" > </form> ``` ```JS Code botton = document.getElementById("sizePicker"); botton.addEventListener('submit', function(event){ event.preventDefault(); var height = document.getElementById("inputHeight").value; var width = document.getElementById("inputWidth").value; makeGrid(height, width); }); ``` did I miss smth? btw only with solo learn compilers I get an error here is the full source code https://github.com/AzerSD/pixelartmaker

22nd Apr 2021, 6:42 PM
AzerSD
AzerSD - avatar
3 Answers
+ 2
I need to use the window.onload function because There's a difference between "immediately execute this when the parser encounters it" and "run this when the entire page has been loaded" (which is what onload does). Sometimes that difference doesn't matter, but sometimes it does - if you need to do things after images have been loaded, for example. 
23rd Apr 2021, 4:46 PM
AzerSD
AzerSD - avatar
+ 4
adding window.onload would fix the problem
22nd Apr 2021, 7:18 PM
Rohit
Rohit - avatar
+ 3
You need to use window.onload as you have done in your SL project 'Location and Population by IP'
22nd Apr 2021, 7:18 PM
ODLNT
ODLNT - avatar