How To Program Disappearing Label Into ASP Textbox

I am developing a VB.NET program. I currently have an ASP Textbox with a label showing inside it. But now the customer has to manually delete this label before entering their own text. How do I get this label to vanish as soon as they begin typing? My script is nearly working now for txtFind. But in this case, it shows a different textbox to display watermark image. How can I reset this watermark to only activate the txtFind textbox instead? And to remove the textbox on left-hand side?

Here is my new ASPX file code:
<script type="text/javascript" language="javascript" >
function GetChart(thepart, thepartdesc, thecolor, row) {
Form1.part_transfer.value = thepart;
Form1.part_desc_transfer.value = thepartdesc;
Form1.submit();
[Code] ......