@Vikin I’ve fixed your code with code formatting. In the future, if you put your code between three backticks (or indent it all by 4 spaces), it will automatically get formatted
```
code here
```
As for your problem, its similar to what you linked to, but probably for a different reason. The issue is that row is null. It’s null because rowId does not match the id of any elemen in your document so a valid element isn’t returned from getElementById, null is. Then trying to access null.style gives you the error.
You need to figure out why rowId is incorrect or why the element by that id doesn’t exist in the document when you expect it to.