Server Control with JavaScript

Question

Building a server control which shows records and allows to select multiple records using checkboxes, I came to the following problem: The control uses some variables such as "CheckedBackColor", which is needed by the client-side JavaScript. The problem is now: if the page has more than one of those controls there can only be one CheckedBackColor hidden field in the HTML. Is there a way to make sure every instance of the control has it's own hidden fields, unique and useable for the JavaScript? The JavaScript code is located in a seperate .JS-file, but I can change that if necessary. Any input appreciated.