Here is an example that my give you an approach you can use
names default to here(1);
dt =
// Open Data Table: Big Class.jmp
// → Data Table( "Big Class" )
Open( "$SAMPLE_DATA/Big Class.jmp" );
nw = new window("Example",
	vlb =vlist box(
	),
	buttonbox("refresh",
		biv << delete;
		wait(2);// the wait() is just to show that the chart has been deleted before the refresh
		vlb<<append(biv = dt << bivariate(x(:height),y(:weight)));
	)
);
vlb<<append(biv = dt << bivariate(x(:height),y(:weight)));
					
				
			
			
				
	Jim