function clickButton(e, buttonid)
{ 
	var bt = document.getElementById(buttonid); 
	if (typeof bt == 'object')
	{ 
		if (!e) e = event;
		
		if (e.keyCode == 13)
		{ 
			if (bt.click)
				bt.click(); 
			else
				if (bt.href)
					window.location = bt.href;
			//bt.click() works only on opera and IE
			return false; 
		} 
	}
}