Toggling click handlers in Javascript

Update: Since this form of toggle() was removed in jQuery 1.9, the solution below does not work anymore. See this question for alternatives.

It looks like toggle() would solve your problem:

$("#mybutton").toggle(myFirstHandlerFunction, mySecondHandlerFunction);

The code above will register myFirstHandlerFunction and mySecondHandlerFunction to be called on alternate clicks.

Just use a boolean to toggle the functionality of the handler, there's no need to juggle which handler is listening:

$('#mybutton').bind('click', myHandlerFunction);
var first = true;

function myHandlerFunction(e) {
    if(first){
        // Code from the first handler here;
    }else{
        // Code from the second handler here;
    }
    first = !first; // Invert `first`
}