>>>How can I do it?
>>
>>The events are all listed in the Properties window (click the button with the lightning icon)
>
>Finally was able to test - the Remove button seems to work.
>
>The Cancel button with my js HideElement code doesn't work, though :(
>
>It has OnClientClick
>

>HideElement('< %=tblProInfo.ClientID % >');

>
>But it shows null for me
>

>function HideElement(what)
>{
>var x = document.getElementById(what);
>alert(x);
>if (x) {
>  x.style.display = 'none' ;
>  }
>  return true ;
> }

Could it be the reason what I have my Cancel button inside the tblProInfo?

I can make it to work with Server side code no problem, but why I can not make it to work with Client side?