Disabling Button Before Executing VB Code To Prevent Duplicate Records?

I need to disable a button after its pressed so the user does not have the ability to click it again as this would replicate the process in some cases.After alot of searching I found some tips - alot of code I found I could not understand.This is what I have come up with:

On page load:
If Me.Page.IsPostBack Then
'lblDetails.Text = "disabled"

[code]....

I also read somewhere that I should use: System.Threading.Thread.Sleep(1000) to delay the process or something - not entirely sure why I would do this though.Although, the problem with my above code is that when the code behind page performs validation checks, it exits sub before executing my INSERT SQL code - so when it does this it also disables the button.I am not entirely sure if the above method is fool proof or whether it is a **** piece of code that won't work 100% of the time.On another website I found a script to put on the actual HTML page with <script> tags:

Code:
<script type="text/javascript">
disableSubmit(frm) {

[code].....