function empty(mixed_var) {
	var key;
	if (mixed_var === "" ||
		mixed_var === 0 ||
		mixed_var === "0" ||
		mixed_var === null ||
		mixed_var === false ||
		mixed_var === undefined
	){
		return true;
	}
	if (typeof mixed_var == 'object') {
		for (key in mixed_var) {
			return false;
		}
		return true;
	}
	return false;
}
function sa_var(variable){
	if(navigator.appName=="Microsoft Internet Explorer"){
		var valor = document.all[variable].value;
	}else{ 
		var valor = document.getElementById(variable).value;
	}
	return valor;
}
function sa_check(variable){
	if(navigator.appName=="Microsoft Internet Explorer"){
		var valor = document.all[variable].checked;
	}else{
		var valor = document.getElementById(variable).checked;
	}
	return valor;
}