function login(){

	userid = eval(document.forms[0].elements['UserId'])
	password = eval(document.forms[0].elements['Password'])
	if (userid.value.length==0) {
		alert("User id necessaria")
		userid.focus()
		return
	}
	if (password.value.length==0) {
		alert("Password necessaria")
		password.focus()
		return
	}
	document.forms[0].submit()
}