function Login(){
	var error_msg;
	var username=$('login_form').username.value;
	var password=$('login_form').password.value;
	$('input_username').className="input-text";
	$('input_password').className="input-text";
	
	if(!username){
		error_msg=lang["login_error_usuario"];
		$('input_username').className="input-text-error";
	} else if(!password){
		error_msg=lang["login_error_contrasena"];
		$('input_password').className="input-text-error";
	} else {
		ExecAjax("actions/login.php","username="+username+"&password="+password,"$('img_loading').show();","","$('img_loading').hide(); LoginEval(transport.responseText);","",true);		
	}
	
	if(error_msg) showError(error_msg);
}

function LoginEval(response){
	if(response=="OK"){
		window.location="index.php";
	} else if(response=="OK2"){
		window.location="index.php?modulo=videochat";
	} else {
		showError(lang["login_combinacion_ivalida"]);
	}	
}
function showError(error_msg){
	$('login_error_msg').hide();
	if(error_msg){
		$('error_msg').innerHTML=error_msg;
		OpenLayer('login_error_msg');
	}
}