[a supprimer] background de mon rectangle

bonjour,

le code suivant permet de créer un rectangle avec du texte.
le texte change de couleur
mai le fond du rectangle non...

/******************************************************************************
* Textback Class
******************************************************************************/

Textback.prototype = new DynamicComponent();
Textback.parent = DynamicComponent.prototype;
Textback.prototype.constructor = Textback;

/******************************************************************************
* Constructor
******************************************************************************/
function Textback()
{
}

/******************************************************************************
* Initialize object
******************************************************************************/
Textback.prototype.init = function(svgId, objectName)
{
    Textback.parent.init.call(this, svgId, objectName, false);
    this.m_SizeFont = GetVisioPropAsInt(this.m_SvgNode, "FontSize");   
    this.m_txtParentElem = getChildNodeFromName(this.m_SvgNode, "text");
    this.m_rectElem = getChildNodeFromName(this.m_SvgNode, "rect");
        removeAllChild(this.m_txtParentElem);
    this.m_txtElem = createTextNode(this.m_txtParentElem, "");   
}

/******************************************************************************
* Callback for refresh event
******************************************************************************/
Textback.prototype.OnRefresh = function()
{
    var value = this.m_arrayValueDefinition[0].getValue();    
    var coltext = colortext;
    var red = Math.round((coltext & 0x000000FF) >> 0);
    var green = Math.round((coltext & 0x0000FF00) >> 8);
    var blue = Math.round((coltext & 0x00FF0000) >> 16);
    var fill = "fill:rgb("+ red +","+ green+","+blue+")";
    var size = "font-size:"+this.m_SizeFont;
    var fontType = "font-family:Arial Unicode MS"
    this.m_txtParentElem.setAttribute("style", fill+";"+size+";"+fontType);

    var colback = colorback;
    red = Math.round((colback & 0x000000FF) >> 0);
    green = Math.round((colback & 0x0000FF00) >> 8);
    blue = Math.round((colback & 0x00FF0000) >> 16);
    var back = "rgb("+ red +","+ green+","+blue+")";

this.m_rectElem.style.backgroundColor = back;

    var st = value;
    this.m_txtElem.nodeValue = st;
}



est ce que quelqu'un a une idée pour ce probléme??

merci d'avance.