CSS Question

I have a reportviewer in a div and through css I want to turn off the border, column and row lines.  Something like this but its not working.
The id of the div is ReportViewerDiv and the id of the ReportViewer is ReportViewer1.  Any help is appreciated. Thanks!
.ReportViewerDiv > tbody > tr > td { border: 0px solid #808080; } Note: This worked by turning everything on.  I want to turn off the ReportViewer lines but have everything else turned on.
tbody > tr > td { border: 1px solid #808080; }