<!-- Inicio de código para botones arriba y abajo escritorio -->
<a href="#" id="abajo"><img src="https://1.bp.blogspot.com/-59F_cDs2BCo/X4IDrpxSTPI/AAAAAAAAHNU/n5x8pDC-0SIqvCepMJ05uW-1i6jvAB65wCLcBGAsYHQ/s0/HueIzqNeg.png" onmouseover="this.src='https://1.bp.blogspot.com/-5mAmek7GZUo/X4IDrD3vTBI/AAAAAAAAHNQ/0drpIgdGaVMVJRjRfY0NH9Y65GhSQ7UTQCLcBGAsYHQ/s0/HueIzqBla.png';" onmouseout="this.src='https://1.bp.blogspot.com/-59F_cDs2BCo/X4IDrpxSTPI/AAAAAAAAHNU/n5x8pDC-0SIqvCepMJ05uW-1i6jvAB65wCLcBGAsYHQ/s0/HueIzqNeg.png';" width="55" height="auto" style="position:fixed; bottom:5px; margin-left:50%;left:-560px;" title='Abajo'/></a>
<script type="text/javascript">
$(document).ready(function() {
$('#abajo').click(function(){ //Id del elemento cliqueable
$('html, body').animate({scrollTop:$(document).height()-$(window).height() }, 3000);
return false;
});
});
</script>
<a href="#" id="arriba"><img border='0' src="https://1.bp.blogspot.com/-WTTIuahuWLI/X4IDrM5fQII/AAAAAAAAHNI/w8AG4cebSu8ddKfU7NaLrXc2x2f-f5l5gCLcBGAsYHQ/s0/HueDerNeg.png" onmouseover="this.src='https://1.bp.blogspot.com/-siP4hWSkCps/X4IDrPz8NnI/AAAAAAAAHNM/EpwE_bq1ONoVR5tw9qKoFq8pK8ou63YEwCLcBGAsYHQ/s0/HueDerBla.png';" onmouseout="this.src='https://1.bp.blogspot.com/-WTTIuahuWLI/X4IDrM5fQII/AAAAAAAAHNI/w8AG4cebSu8ddKfU7NaLrXc2x2f-f5l5gCLcBGAsYHQ/s0/HueDerNeg.png';" width="55" height="auto" style="position:fixed; bottom:5px; margin-right:50%;right:-560px;" title='Arriba'/></a>
<script type="text/javascript">
$(document).ready(function() {
$('#arriba').click(function(){ //Id del elemento cliqueable
$('html, body').animate({scrollTop:0}, 3000);
return false;
});
});
</script>
<!-- Fin de código para botones arriba y abajo escritorio -->