Adding DEM to the following program doesn't work?

Hi,

I am a beginner and want to apply DEM (Digital Elevation Model) to the following code, Any quick ideas?!

figure ('Name', 'The State of Florida') % Create a new figure
usamap('Florida') % Construct map axes for State of Florida
states = shaperead('usastatehi', 'UseGeoCoords', true); % Read vector features
geoshow(states) % Display map geographic data structure