/////////////////////////////////////////////////////////////////////

var FloatLayers       = new Array();
var FloatLayersByName = new Array();

function addFloatLayer(n,offX,offY,spd){new FloatLayer(n,offX,offY,spd);}
function getFloatLayer(n){return FloatLayersByName[n];}
function alignFloatLayers(){for(var i=0;i<FloatLayers.length;i++)FloatLayers[i].align();}

function getXCoord(el) {
    x=0;
    while(el){
        x+=el.offsetLeft;
        el=el.offsetParent;
    }
    return x;
}
function getYCoord(el) {
    y=0;
    while(el){
        y+=el.offsetTop;
        el=el.offsetParent;
    }
    return y;
}

/////////////////////////////////////////////////////////////////////

FloatLayer.prototype.setFloatToTop=setTopFloater;
FloatLayer.prototype.setFloatToBottom=setBottomFloater;
FloatLayer.prototype.setFloatToLeft=setLeftFloater;
FloatLayer.prototype.setFloatToRight=setRightFloater;
FloatLayer.prototype.initialize=defineFloater;
FloatLayer.prototype.adjust=adjustFloater;
FloatLayer.prototype.align=alignFloater;

function FloatLayer(n, offX, offY, spd) {
    this.index=FloatLayers.length;

    FloatLayers.push(this);
    FloatLayersByName[n] = this;

    this.name    = n;
    this.floatX  = 0;
    this.floatY  = 0;
    this.tm      = null;
    this.steps   = spd;
    this.alignHorizontal=(offX>=0) ? leftFloater : rightFloater;
    this.alignVertical  =(offY>=0) ? topFloater : bottomFloater;
    this.ifloatX = Math.abs(offX);
    this.ifloatY = Math.abs(offY);
}

/////////////////////////////////////////////////////////////////////

function defineFloater(){
    this.layer  = document.getElementById(this.name);
    this.width  = this.layer.offsetWidth;
    this.height = this.layer.offsetHeight;
    this.prevX  = this.layer.offsetLeft;
    this.prevY  = this.layer.offsetTop;
}

function adjustFloater() {
    this.tm=null;
    if(this.layer.style.position!='absolute')return;

    var dx = Math.abs(this.floatX-this.prevX);
    var dy = Math.abs(this.floatY-this.prevY);

    if (dx < this.steps/2)
        cx = (dx>=1) ? 1 : 0;
    else
        cx = Math.round(dx/this.steps);

    if (dy < this.steps/2)
        cy = (dy>=1) ? 1 : 0;
    else
        cy = Math.round(dy/this.steps);

    if (this.floatX > this.prevX)
        this.prevX += cx;
    else if (this.floatX < this.prevX)
        this.prevX -= cx;

    if (this.floatY > this.prevY)
        this.prevY += cy;
    else if (this.floatY < this.prevY)
        this.prevY -= cy;

    this.layer.style.left = this.prevX;
    this.layer.style.top  = this.prevY;

    if (cx!=0||cy!=0){
        if(this.tm==null)this.tm=setTimeout('FloatLayers['+this.index+'].adjust()',50);
    }else
        alignFloatLayers();
}

function setLeftFloater(){this.alignHorizontal=leftFloater;}
function setRightFloater(){this.alignHorizontal=rightFloater;}
function setTopFloater(){this.alignVertical=topFloater;}
function setBottomFloater(){this.alignVertical=bottomFloater;}

function leftFloater(){this.floatX = document.body.scrollLeft + this.ifloatX;}
function topFloater(){this.floatY = document.body.scrollTop + this.ifloatY;}
function rightFloater(){this.floatX = document.body.scrollLeft + document.body.clientWidth - this.ifloatX - this.width;}
function bottomFloater(){this.floatY = document.body.scrollTop + document.body.clientHeight - this.ifloatY - this.height;}

function alignFloater(){
    if(this.layer==null)this.initialize();
    this.alignHorizontal();
    this.alignVertical();
    if(this.prevX!=this.floatX || this.prevY!=this.floatY){
        if(this.tm==null)this.tm=setTimeout('FloatLayers['+this.index+'].adjust()',50);
    }
}