c# - ASP.NET : getting 'currentStyle' is null or not an object when adding webpanel dynamicly -

i added dynamicly infragistics webpanel in codebehind using : placeholder.controls.add(ctlwebpanel); got javascript error in asp.net page in runtime : 'currentstyle' null or not object

how set style remove error ?

thanks brian concern. find out missing css style class. setted property cssclass dynamicly when creating control , works ! still don't understand why it's mandatory set dynamicly when don't have if added directly in design.