if (document.images) {
  var boton1_off = new Image();
  boton1_off.src = "./img/inicio.jpg";
  var boton1_on = new Image();
  boton1_on.src = "./img/inicio_sup.jpg";
  
  var boton2_off = new Image();
  boton2_off.src = "./img/usuarios.jpg";
  var boton2_on = new Image();
  boton2_on.src = "./img/usuarios_sup.jpg";
  
  var boton3_off = new Image();
  boton3_off.src = "./img/zona_segura.jpg";
  var boton3_on = new Image();
  boton3_on.src = "./img/zona_segura_sup.jpg";
  
  var boton4_off = new Image();
  boton4_off.src = "./img/agenda.jpg";
  var boton4_on = new Image();
  boton4_on.src = "./img/agenda_sup.jpg";
  
  var boton5_off = new Image();
  boton5_off.src = "./img/faq.jpg";
  var boton5_on = new Image();
  boton5_on.src = "./img/faq_sup.jpg";
  
  var boton6_off = new Image();
  boton6_off.src = "./img/sugerencias.jpg";
  var boton6_on = new Image();
  boton6_on.src = "./img/sugerencias_sup.jpg";
  
  // boton buscador **************************************
  var boton7_off = new Image();
  boton7_off.src = "./img/btn_search_all.gif";
  var boton7_on = new Image();
  boton7_on.src = "./img/btn_search_all_On.gif";
}


  
function ini(boton) {
  //boton inicio
  if (document.images) {
    if (boton == 'boton1') {
      document.images[boton].src = boton1_on.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton2') {
      document.images[boton].src = boton2_on.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton3') {
      document.images[boton].src = boton3_on.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton4') {
      document.images[boton].src = boton4_on.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton5') {
      document.images[boton].src = boton5_on.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton6') {
      document.images[boton].src = boton6_on.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton7') {
      document.images[boton].src = boton7_on.src;
    }
  }
} 

 
  // Carga de imagen cuando el ratón abandona el área de la imagen 
function out(boton) {
  if (document.images) {
    if (boton == 'boton1') {
      document.images[boton].src = boton1_off.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton2') {
      document.images[boton].src = boton2_off.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton3') {
      document.images[boton].src = boton3_off.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton4') {
      document.images[boton].src = boton4_off.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton5') {
      document.images[boton].src = boton5_off.src;
    }
  }
  
  if (document.images) {
    if (boton == 'boton6') {
      document.images[boton].src = boton6_off.src;
    }
  }
  
   if (document.images) {
    if (boton == 'boton7') {
      document.images[boton].src = boton7_off.src;
    }
  }
}