-The eSpace take in CountryCode input parameter, example, http://localhost/TestAjaxRefresh/Test.aspx?CountryCode=UK
onload the button is either enabled or disabled based on the input parameter, when COUNTRY.Flag = true/false.

The AJAXRefresh is used in a screen action to provide this functionality,-how would you perform this same behaviour/action in a screen presentation?
just use an expression in the enabled variable?

you don't need ajax-refresh in an onload, because it's load for the first time anyways.
Problem solved, and optimised by making use of Get<ENTITY>.