function cambiar(mensaje)
{
  document.getElementById('combi').innerHTML = mensaje;
}
var Cookie =
    {
        read: function (name)
        {
            var arrCookies = document.cookie.split ('; ');
            for (var i=0; i<arrCookies.length; i++)
            {
                var arrCookie = arrCookies[i].split ('=');
                
                if (arrCookie[0] == name)
                {
                    return decodeURIComponent (arrCookie[1]);
                }
            }
            return false;
        },
    
        write: function (name, value, expires, path)
        {
            if (expires)
            {
                var date = new Date ();
                date.setTime (date.getTime () + (((((expires * 24) * 60) * 60) * 1000)));
                expires = '; expires=' + date.toGMTString ();
            }
            else expires = '';
    
            if (!path) path = '/';
    
            document.cookie = name+'='+encodeURIComponent (value)+expires+'; path='+path;
        },
    
        remove: function (name)
        {
            this.write (name, '', -1);
        }
    }
    function browserSupportsCookies()
    {
        Cookie.write('cookiesEnabled', 1);
        var boolCookiesEnabled = Cookie.read('cookiesEnabled');
        Cookie.remove('cookiesEnabled');
        if (boolCookiesEnabled != 1)
        {
            return false;
        }
        return true;
    }
    function browserSupportsAjax()
    {
        if (typeof XMLHttpRequest == "undefined" && typeof ActiveXObject == "undefined" && window.createRequest == "undefined")
        {
            return false;
        }
        return true
    }
    function ActiveXEnabledOrUnnecessary ()
    {
        if (typeof ActiveXObject != "undefined")
        {
            var xhr = null;
            try{
                xhr=new ActiveXObject("Msxml2.XMLHTTP");
            }catch (e){
                try{
                    xhr=new ActiveXObject("Microsoft.XMLHTTP");
                }catch (e2){
                    try{
                        xhr=new ActiveXObject("Msxml2.XMLHTTP.4.0");
                    }catch (e3){
                        xhr=null;
                    }
                }
            }
            if (xhr == null)
            {
                return false
            }
        }
        
        return true;
    }
	if (!browserSupportsCookies())
    {
    alert("Cookies estan deshabilitadas");
    }else{
    if (!browserSupportsAjax())
    {
      document.getElementById('form').text = 'AJAX no soportado';      
    }else{
    if (!ActiveXEnabledOrUnnecessary())
    {
      document.getElementById('form').text = 'ActiveX esta deshabilitado';
    }else{
      function POST_AJAX(url, variables) {
        objeto = false;
		//creamos el onjeto XMLHttpRequest para poder enviar datos mediante ajax
        if (window.XMLHttpRequest) { // Mozilla, Safari,...
           objeto = new XMLHttpRequest();
           if (objeto.overrideMimeType) {
           	objeto.overrideMimeType('text/xml');
           }
        } else if (window.ActiveXObject) { // IE
           try {
              objeto = new ActiveXObject("Msxml2.XMLHTTP");
           } catch (e) {
              try {
                 objeto = new ActiveXObject("Microsoft.XMLHTTP");
              } catch (e) {}
           }
        }
        if (!objeto) {
           alert("No se puede crear la instancia XMLHTTP");
           return false;
        } 
		     
        objeto.onreadystatechange = avisos; 
        objeto.open("POST", url, true);
        objeto.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        objeto.setRequestHeader("Content-length", variables.length);
        objeto.setRequestHeader("Connection", "close");
        objeto.send(variables);
	  }
	  function enviar(id_form,n) {  
		if (n=='1')
		 {
		  
		  document.getElementById('inp_enviar').innerHTML = '<?php boton102() ?>';
	      if (vacio(document.getElementById(id_form).user.value)==false || vacio(document.getElementById(id_form).pass.value)==false)
		   {
			
			document.getElementById('inp_enviar').innerHTML = '<?php boton102() ?>';
		   }
	      else 
		   {
		    var Formulario = document.getElementById(id_form);
		    var longitudFormulario = Formulario.elements.length;
		    var variables = "";
		    var sepCampos = "";
		    for (var i=0; i<=Formulario.elements.length-1; i++)
		      {
		       variables += sepCampos+Formulario.elements[i].name + '=' + encodeURI(Formulario.elements[i].value);
               sepCampos="&";
              }
			 //indice para saber si envio formulario
		    variables += '&n=' + n; 
		    POST_AJAX('checar.php', variables);
		   }
		 }
		else 
		 {
		    variables = 'n=' + n; 
		    POST_AJAX('checar.php', variables);
		 }
      }
    
      function avisos() {
	     if ((objeto.readyState==4) && (objeto.status==200))                     
	       {
		    document.getElementById('form').innerHTML = objeto.responseText;              
	       }
	  }
	  
	 enviar('login','0');
	  function vacio(q) {
         for ( i = 0; i < q.length; i++ ) {
           if ( q.charAt(i) != " " ) { return true }
         }
         return false
	  }
	}}}