var showMore;  

function movertab(dir){ 
   if(dir == "u") {
    scrollup();
   }
   if(dir == "d") {
    scrolldown();
   }
  }
  
  function scrollup() { 
   tpos = parseInt(document.getElementById("tabtexto").style.top);
   t = Math.abs(tpos);
   document.getElementById("tabtexto").style.top = (-1)*(t + 5); 
   showMore = window.setTimeout("scrollup()",50);    
  }

  function scrolldown() {
   tpos = parseInt(document.getElementById("tabtexto").style.top);
   t = Math.abs(tpos);
   if(t > 0) {
    document.getElementById("tabtexto").style.top = (-1)*(t - 5);
   }
   if(t >= 10) {
    showMore = window.setTimeout("scrolldown()",50);  
   }
  }

  function cambiarimg(elem,imgfile){ 
   document.getElementById(elem).src="images/"+imgfile+".gif";    
  }