为什么这个jQuery代码可以在Firefox中运行，但不适用于Chrome或Safari？

I'm using jQuery to highlight (by changing bg color) some table cells. I want the button (a simple anchor) to be given the class name 'selected' when clicked and I want certain table cells below the buttons to highlight. When you click the same button again, it deselects and removes the highlights from the table cells. When you click a different button, it removes the other highlights and switches to the new appropriate ones.I'm using jQuery to highlight (by changing bg c