How to set the first node of a tree as selected by default

Hi

How do i set the first node of the tree by default? I want to set the first node of the tree to be selected

I tried , yardTree.fireSelect("node"); but it didnt work out

var yardTree = new sap.ui.commons.Tree({


.....





select : [ function(oEvent) {





var control = oEvent.getSource();


var nodeId = oEvent.getParameter("node").getId();
//alert("nodeId::"+nodeId);


var selectedYardNo = oEvent.getParameter("node").getText();


//
alert("selectedYardNo::"+selectedYardNo);



//call the odata


}, this ]







});






yardTree.setModel(jsonTreeModel);





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





var yardNo = oData.results[i].YardNo;





var node = new sap.ui.commons.TreeNode();







node.setText(yardNo);


//


    yardTree.addNode(node);





}





//selec the first node of the tree by default


//


var nodes [] = yardTree.getNodes();


//


yardTree.fireSelect(nodes[0]);


//

Any help?

Thanks

Sandip