function toSpans(span) {
  var str=span.firstChild.data;
  var a=str.length;
  span.removeChild(span.firstChild);
  for(var i=0; i<a; i++) {
    var theSpan=document.createElement("SPAN");
    theSpan.appendChild(document.createTextNode(str.charAt(i)));
    span.appendChild(theSpan);
  }
}
function RainbowSpan(span, hue, deg, brt, spd, hspd) {
    this.deg=(deg==null?360:Math.abs(deg));
    this.hue=(hue==null?0:Math.abs(hue)%360);
    this.hspd=(hspd==null?3:Math.abs(hspd)%360);
    this.length=span.firstChild.data.length;
    this.span=span;
    this.speed=(spd==null?50:Math.abs(spd));
    this.hInc=this.deg/this.length;
    this.brt=(brt==null?255:Math.abs(brt)%256);
    this.timer=null;
    toSpans(span);
    this.moveRainbow();
}

RainbowSpan.prototype.moveRainbow = function() {
  if(this.hue>359) this.hue-=360;
  var color;
  var b=this.brt;
  var a=this.length;
  var h=this.hue;

  for(var i=0; i<a; i++) {

    if(h>359) h-=360;

    if(h<60) { color=Math.floor(((h)/60)*b); red=b;grn=color;blu=0; }
    else if(h<120) { color=Math.floor(((h-60)/60)*b); red=b-color;grn=b;blu=0; }
    else if(h<180) { color=Math.floor(((h-120)/60)*b); red=0;grn=b;blu=color; }
    else if(h<240) { color=Math.floor(((h-180)/60)*b); red=0;grn=b-color;blu=b; }
    else if(h<300) { color=Math.floor(((h-240)/60)*b); red=color;grn=0;blu=b; }
    else { color=Math.floor(((h-300)/60)*b); red=b;grn=0;blu=b-color; }

    h+=this.hInc;

    this.span.childNodes[i].style.color="rgb("+red+", "+grn+", "+blu+")";
  }
  this.hue+=this.hspd;
}