function detecta_navegador(){
 
navegador_cod=navigator.appName;
user_cod=navigator.userAgent;
plataforma_cod=navigator.platform;
navegador_ver=navigator.appVersion;

	if(navegador_cod.indexOf("Explorer") != -1){
		if(navegador_ver.indexOf("MSIE 7") != -1){
			return "explorer7";
		}
		else if(navegador_ver.indexOf("MSIE 8") != -1){
			return "explorer8";
		}
		else{
			if(navegador_ver.indexOf("MSIE 6") != -1){
				return "explorer"; 
			} 
		}
	}else{  
		if(user_cod.indexOf("Safari") != -1 ){
			return "safari";
		}
		else{	
			if(user_cod.indexOf("Firefox") != -1 ){
				return "firefox";
			}	
		}
	}
}


function detecta_plataforma(){
navegador_cod=navigator.appName;
user_cod=navigator.userAgent;
plataforma_cod=navigator.platform;
	
 if(plataforma_cod.indexOf("Win") != -1){
      return "windows";
  }

  else{  
  
	if(plataforma_cod.indexOf("Mac") != -1 ){
		return "mac";
		}
		else{	
		if(user_cod.indexOf("Unix") != -1 ){
		return "linux";
		}
		}	
  }
}

function aminusculas(cadena){
	cadena_rest=cadena.substr(1);
		cadena_rest=cadena_rest.toLowerCase();
		prim_letra=cadena.substr(0,1);
		prim_letra=prim_letra.toUpperCase();
		cadena=prim_letra+cadena_rest;
	return cadena;
}

function checkMail(cadena_mail){
		ext=cadena_mail.substring(cadena_mail.lastIndexOf("."),cadena_mail.length);
		if(ext.length<5 && ext.length>1){
			var Template = /^[a-z][a-z-_0-9.]+@[a-z-_=>0-9.]+.[a-z]{2,3}$/i 
			return (Template.test(cadena_mail)) ? 1 : 0 
			if (Template.test(cadena_mail) == 0){
				return false;
			}else{			
				return true;
			}
		}else{
			return false;
		}
}
function nwsltr(){
	if (checkMail(document.newsletter.nlt.value)==0){
	alert('El email no es correcto');
	document.newsletter.nlt.focus();}
	else{
	document.newsletter.submit();
	}
}