function chkLogin(e) {
	var w3DOM = window.addEventListener;
	var dsLogin = document.getElementById("dsLogin");
	var dsPassword = document.getElementById("dsPassword");
	var msgError = '';

	if(trim(dsLogin.value) == '') {
		msgError += "- Preencha o campo Login\n";
	}

	if(trim(dsPassword.value) == '') {
		msgError += "- Preencha o campo Senha\n";
	}

	if(msgError != "") {
		alert(msgError);
		if(w3DOM) {
			e.preventDefault();
		}
		else {
			return false;
		}
	}
}

function init() {
	var frmLogin = document.getElementById("frmLogin");
	addEvent(frmLogin, "submit", chkLogin);
}

addEvent(window, "load", init);