[jQuery] document.onmousedown=selectmouse vs $(document).mousedown(function(){})

[jQuery] document.onmousedown=selectmouse vs $(document).mousedown(function(){})


this is interesting:
I have a standard function in JS, and call it like so:
document.onmousedown=trackmouse
function trackmouse(){...}
works very nicely.
I tired to make it happen jQuery-style, but no dice.
$(document).mousedown(function(){})
Of course my function is inside an extender
jQuery.fn.extend({ trackmouse: function(){...});
It's more of an exercise really, because the plain JS syntax is
actually less obtrusive than the jQuery version.