Use Javascript variable in object name?

I am using CKEditor, and, when referring to the CKEditor instance, I need to use a variable. But, since calling the instance is a object, I am really not sure how to do this. I am using: ``` CKEDITOR.instances.textarea123.insertHtml('<p>Whatever</p>'); ``` The issue is, I need 123 to be a variable, because I need to change the instance based on the editor page that is loaded. So, how can I use a variable in an object name? For obvious reasons the following does not work, but I need to achieve what it is "pretending" to do: ``` var id = 354; CKEDITOR.instances.textarea+id+.insertHtml('<p>Whatever</p>'); ```