button click?

Can i count how many times a button is clicked on a web page? Can i restrict user to click twice on the same button??

 

yeah, if the user clicked on that button once, save it to a variable where 0 i not-clicked and 1 is clicked

 

you can also use session or cookie to track youre users click.

 

session is good track easily

 

Yes. very simple to apply. use client side script.
Use something like:
<input type="button" value="Click Me!" onclick="this.disabled=true;this.form.submit();">