How to know if the Page is in Edit Mode - JavaScript ?

For a page we need to use:

var pageMode = document.forms[MSOWebPartPageFormName].MSOLayout_InDesignMode.value;

if (pageMode == 1)
{
    // page is in edit mode
}
else
{
    // page is in browse mode
}

and for wiki pages:

var pageMode = document.forms[MSOWebPartPageFormName]._wikiPageMode.value;

if (pageMode == "Edit")
{
    // page is in edit mode
}
else
{
    // page is in browse mode
}

This will refer to a value of the following html input control, which is rendering on the page when it is in edit mode: