[jQuery] removeClass error

[Shelane]

Error: b.className has no properties
Source File: http://mymachine/javascripts/jQuery/jquery.pack.js
Line: 11


this occurs when I do this:
var doc = $(this);
function checkIt(){
$(doc).removeClass('RedText');
}

it also occurs when I do this:
function checkIt(){
$(this).removeClass('RedText');
}