Call function when checkbox is clicked in JavaScript?

I've created some checkboxes dynamically using JavaScript (below), any ideas on how to call a function when a checkbox is clicked?

var eng_types = table[3].slice(3);
for(var i in eng_types) {
    var name = eng_types[i];

    // create the necessary elements
    var label= document.createElement("label");
    var description = document.createTextNode(name);
    var checkbox = document.createElement("input");

    checkbox.type = "checkbox";    // make the element a checkbox
    checkbox.name = i;      // give it a name we can check
    checkbox.value = name;         // make its value "pair"

    label.appendChild(checkbox);   // add the box to the element
    label.appendChild(description);// add the description to the element

    // add the label element to your div
    document.getElementById('eng_options').appendChild(label);

}

Any pointers on how to make each checkbox appear on a new line would also be appreciated.

Thanks in advance!