Best way to remove an event handler in jQuery?

Question

I have an input type=\"image\". This acts like the cell notes in Microsoft Excel. If someone enters a number into the text box that this input-image

Answer 1

If event is attached this way, and the target is to be unattached:

$('#container').on('click','span',function(eo){
    alert(1);

    $(this).off(); //seams easy, but does not work

    $('#container').off('click','span'); //clears click event for every span

    $(this).on("click",function(){return false;}); //this works.

});​