[javascript] Submitting the value of a disabled input field

I know this is old but I just ran into this problem and none of the answers are suitable. nickf's solution works but it requires javascript. The best way is to disable the field and still pass the value is to use a hidden input field to pass the value to the form. For example,

<input type="text" value="22.2222" disabled="disabled" />
<input type="hidden" name="lat" value="22.2222" />

This way the value is passed but the user sees the greyed out field. The readonly attribute does not gray it out.