A One-Time Event function

onetime.js

// source: http://www.sitepoint.com/create-one-time-events-javascript/?

// create a one-time event
function onetime(node, type, callback) {
 
    // create event
    node.addEventListener(type, function(e) {
        // remove event
        e.target.removeEventListener(e.type, arguments.callee);
        // call handler
        return callback(e);
    });
 
}

// one-time event
onetime(document.getElementById("myelement"), "click", handler);
 
// handler function
function handler(e) {
    alert("You'll only see this once!");
}