Sounds like you are trying to create a watermarked text box. The code below will remove the watermark when focus is in the text box. You can also hook the blur event and put the watermark back if the textbox is still empty. I'll leave that as an exercise.
<input id="mytextbox" type="text" class="mytextbox" value="click to edit" />
$().ready(function(){
$(".mytextbox").focus(function(){
$(this).val('');
});
});