function svuota(ID)
	{
	var text = document.getElementById(ID);
	if (text.value == "username" | text.value == "password")
	text.value = "";		
	else
	text.value = text.value
	}

function popola(ID)
	{
	var text = document.getElementById(ID);
	if (ID == "user" & text.value == "")
	text.value = "username";		
	if (ID == "psw" & text.value == "")
	text.value = "password";		
	}