function buttonalert(event,url,message)
{
    var button;
    if (event.which == null)
       button= (event.button < 2) ? "LEFT" :
                 ((event.button == 4) ? "MIDDLE" : "RIGHT");
    else
       button= (event.which < 2) ? "LEFT" :
                 ((event.which == 2) ? "MIDDLE" : "RIGHT");
				 
	if (button == "LEFT") 
	{
		document.location = url;
	}
	else
	{
	    alert(message);
    	dont(event);
	}
}

function dont(event)
{
    if (event.preventDefault)
        event.preventDefault();
    else
        event.returnValue= false;
     return false;
}