This type of logic seems better suited for a client side script, but in any case, you can not use that logic on the backend.
The rasing of the click event method signifies that the button was clicked so your logic would be redundant inside of a click event handler as (even if there was a clicked property) it would always return true.
If, however, your intent is to use one event handler for multiple buttons you would do something like this to determine which button raised the event:
private void foo(object sender, System.EventArgs e)
LinkButton lb = (LinkButton)sender;
if(lb.ID == "linkbutton1")
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