need to adjust script to work on certian areas of page only

[webguync]

I have some javascript which makes all text on a page unselectable. Works great. I only want some of the text unselectable though, not all on the page. I can give the text I need selected a class, but how would I adjust the JS?

 

below is the code

 

<script type="text/javascript">
document.onselectstart=new Function('return false');function ds(e){return false;}function ra(){return true;}document.onmousedown=ds;document.onclick=ra;
</script>