Unable to check checkbox in Internet Explorer

[renaatdemuynck]

Unable to set the checkbox in the checked state in Internet Explorer. This is because the default action in IE for clicking an indeterminate checkbox, is to set it to unchecked (all other browsers set it ti checked).

[renaatdemuynck]

W3C states the following:

The pre-click activation steps consist of setting the element's checkedness to its opposite value (i.e. true if it is false, false if it is true), and of setting the element's indeterminate IDL attribute to false.

Since the checkedness is false when a checkbox is indeterminate, it MUST be set to a checked state.