Browser running upon checkbox onToggle

Hi, I have a checkbox with an onToggle, where if ticked, enables an inputfield to be entered, and when unticked, disables the field.

When I tick the checkbox, the inputfield opens, which is correct, but this also triggers the browser's loading bar to start running (Internet Explorer). Can I get some advise on why this is happening, or how I can solve this?

I tried on Firefox, and it doesn't happen there, but reloads my screen scrollbar to the top again upon ticking the box.