Scrollbar of Tabstrip Design Studio

Hello experts,

I am working in DS 1.5.

I use Tabstrip in my application and I set the properties like this: , the problem is when I zoom in the window's size of the application, the elements will be hiden without scrollbar.

If I fix the width and height of Tabstrip, the scrollbar will appear while zooming in the window's size, but the tabstrip cannot fill to the full for all sizes of the screen.

So how can I set the width and height to “auto”,and I zoom in the window, the scrollbar will appear?

PS:I didn't find where to set css for the tabstrip, otherwise I can set css by " overflow:scroll;", did I?

Thanks!