/* validar una dirección de e-mail */
function checkEmail(address) {
	if ((address == "") || (address.indexOf('@') == -1) || (address.indexOf('.') == -1) || (address.indexOf(';') != -1) || (address.indexOf(':') != -1) || (address.indexOf(',') != -1) || (address.indexOf('&') != -1) || (address.indexOf('/') != -1))
		return false;

	return true;
}

/* restringir el tamaño mímimo de una cadena */
function strLong(objeto, longitud) {
	if (objeto.value.length < longitud)
		return false;

	return true;
}

/* chequear si una cadena contiene espacios en blanco */
function checkBlank(objeto) {
	if (objeto.indexOf(' ') != -1)
		return false;

	return true;
}


/* */
function lib_bwcheck(){ // chequeamos el navegador
	this.ver = navigator.appVersion
	this.agent = navigator.userAgent
	this.dom = document.getElementById?1:0
	this.opera5 = this.agent.indexOf("Opera 5")>-1
	this.ie5 = (this.ver.indexOf("MSIE 5")>-1 && this.dom && !this.opera5)?1:0;
	this.ie6 = (this.ver.indexOf("MSIE 6")>-1 && this.dom && !this.opera5)?1:0;
	this.ie4 = (document.all && !this.dom && !this.opera5)?1:0;
	this.ie = this.ie4||this.ie5||this.ie6
	this.mac = this.agent.indexOf("Mac")>-1
	this.ns6 = (this.dom && parseInt(this.ver) >= 5) ?1:0;
	this.ns4 = (document.layers && !this.dom)?1:0;
	this.bw = (this.ie6 || this.ie5 || this.ie4 || this.ns4 || this.ns6 || this.opera5)
	return this
}
var bw = new lib_bwcheck()


/* ChangeText -> constructor de objetos */
function makeObj(obj) {
   	this.css = bw.dom?document.getElementById(obj).style:bw.ie4?document.all[obj].style:bw.ns4?document.layers[obj]:0;
   	this.writeref = bw.dom?document.getElementById(obj):bw.ie4?document.all[obj]:bw.ns4?document.layers[obj].document:0;
	this.writeIt = b_writeIt;
}

function b_writeIt(text, num) {
	if (bw.ns4) {
		this.writeref.write(text)
		this.writeref.close()
	} else
		this.writeref.innerHTML = messages[num]
}

/* expandir los menús */
function expandir(obj, alto) {
	oMenu = new makeObj(obj);

	if (bw.ie) {
		if (oMenu.writeref.style.display == 'none')
			oMenu.writeref.style.display = 'list-item';
		else
			oMenu.writeref.style.display = "none";
	} else {
		if (oMenu.css.visibility == "hidden") {
			oMenu.css.visibility = "visible";
			oMenu.css.height = "" + alto + "px";
		} else {
			oMenu.css.visibility = "hidden";
			oMenu.css.height = "0em";
		}
	}
}

/* contraer los menús */
function contraer(obj) {
	oMenu = new makeObj(obj);

	if (bw.ie) {
		oMenu.writeref.style.display = "none";
	} else {
		oMenu.css.visibility = "hidden";
		oMenu.css.height = "0em";
	}
}


/* validar login de acceso a la extranet */
function validar_login_extranet(frm) {
	var validado = true;
	var msg = "Atención!\n";
	
	if (frm.username.value ==  "") {
		validado = false;
		msg += "Falta ingresar el nombre de usuario";
		frm.username.focus();
	} else if (frm.password.value ==  "") {
		validado = false;
		msg += "Falta ingresar la contraseña";
		frm.password.focus();
	}
	
	if (!validado)
		alert(msg);
		
	return validado;
}