Non functioning javascript

Hi,

I have this small bit of script

                <script type="text/javascript" language="javascript"/>
                if(document.images){
                                var image = document.getElementById('sentence');
                                alert(image.src);
                }
                </script>

This was merely to test; it brings back “undefined” in the alert box. When i take out all the script and replace it with alert(“hello”) it displays that ok.

Any ideas?