how to resize the reportviewer so it fills the webform ?

how to resize the reportviewer so it fills the webform ?

this its my aspx webform with the report viewer

   <div style="Width:auto;">

   <form id="form1" runat="server" style="width:100%; height:100%;">
     

    <CR:CrystalReportViewer  ID="rptviewer" runat="server" AutoDataBind="true" DisplayStatusbar="False"--%>
            EnableToolTips="False" HasCrystalLogo="False" HasSearchButton="False" HasDrilldownTabs="False"
            HasDrillUpButton="False" HasGotoPageButton="False" HasPageNavigationButtons="False" HasZoomFactorList="False"
            HasToggleGroupTreeButton="False" HasToggleParameterPanelButton="False" ToolPanelView="None" Width="100%" Height="900px"  BestFitPage="true" AsyncRendering="False" SizeToReportContent="True"/>
   
    </form>
   </div>

this its how the window its opened

function openWindow(url, width, height) {
    var w = window.open(url, '', 'width=' + width + ',height=' + height + ',toolbar=0,status=0,location=0,menubar=0,directories=0,resizable=1,scrollbars=1');
    //var w = window.open(url, '','toolbar=0,status=0,location=0,menubar=0,directories=0,resizable=1,scrollbars=1');
    w.focus();
}

i have tried to set resizable=0 to not allow to resize the window but only works on ie on firefox its ignored

what´s happening with this code the toolbar its resized but the report its not being resized

thanks