How to easily check or uncheck all textboxes with JQuery

How to set the default OPTION in a SELECT list with the jQuery framework.

I recently encountered this problem using Javascript and Internet Explorer. It worked perfectly fine in other browsers although (for a change) I think MSHTML has got this right enforcing good practice.

Object Doesnt Support this Property or Method can occur in Internet Explorer when you declare a variable that has the same name as a document object.