Question

When Unlimited is checked, remove the input box. That works. However, when the checkbox is unchecked the input box wont show back up.

<script type="text/javascript">
    function getQuantity() {
        var checkbox = document.getElementById("unlimited");
        var qty = document.getElementById("quantityspace");
        if(checkbox.checked == true){
             qty.style.display = 'none';
        }else if(checkbox.checked == false) {
             qty.stlye.display = '<input type="text" id="quantity" size="4" value="1" name="quantity" />';
        }
    }
</script>

<input type="checkbox" id="unlimited" name="unlimited" value="x" onClick="getQuantity(); " /> Unlimited? <span id="quantityspace">or specify:
<input type="text" id="quantity" size="4" value="1" name="quantity" /></span>

Answer 1

qty.stlye.display = '<input type="text" id="quantity" 
size="4" value="1" name="quantity" />';

should be:

qty.style.display = 'inline'; // or block

display is a property of the already existing input tag. You don’t need to assign the entire tag to the property to make it show up again — in fact that’s dead wrong. Simply assign that property a new valid value for display, like inline, inline-block or block and it will show up again.