setStyle of last row

Hello,

how can I change the colour of the last row in the grid?
I should be done when the grid is started.
I use the 2.x version.

Thx.

var lastrow=length(myData-1);

obj.defineRowProperty("Mycolor", function(row){  
return  row==lastrow ? "#AA0000" : null;  
});  

obj.getRowTemplate().setStyle("color", function(){  
return this.getRowProperty("Mycolor");  
});  

Sorry
var lastrow=length(myData)-1;  

var lastrow=myData.length-1;