Pls suggest me how to add a external css to a view?

You can apply an external stylesheet via the IncludeStylesheet
control
(http://www.ajax-softwareag.com/articles/N7M0TP/DesignerOnlineHelp/caf_include_stylesheet.html),
by setting the control’s value to the url of the stylesheet.

Most other controls include an (expert) cssClass property, which you
can use to apply classes defined in the external stylesheet to the
controls. The cssClass property simply passes thru its value to the
control’s main html element; so for example, if you set the cssClass
property of a BlockPanel to “foo bar”, the BlockPanel will be rendered
like the following:

Thanks,
Thomas