function showMenu(elem_id, shown){

 	var el = document.getElementById(elem_id);
 	
	if(shown=="true"){
		el.style.display="block";
			
	}else{
		el.style.display="none";
		
		if(elem_id == "div_civili"){
			document.getElementById("img_civili").src="images/menu_civili.gif";
		}else
		if(elem_id == "div_industriali"){
			document.getElementById("img_industriali").src="images/menu_industriali.gif";
		}
	}
	
}
function hide_all(){
	document.getElementById("div_civili").style.display="none";
	document.getElementById("img_civili").src="images/menu_civili.gif";
	
	document.getElementById("div_industriali").style.display="none";
	document.getElementById("img_industriali").src="images/menu_industriali.gif";
}
function search(){
	if(document.form_ricerca.word.value==""){
		alert("Specificare la parola o la frase da cercare");
		document.form_ricerca.word.focus();
	}else{
		document.form_ricerca.submit();
	}
}