There is a sample mashup (in EMML) installed with Presto that does something similar - it should give you a basic idea. If you start the Mashup Server, go to the Presto home page (http://localhost:8080/presto) and log in. Then click Samples > Launch EMML Mashup Test Navigator.
In this sample page, look under EMML Features for the GEO Annotate mashup. The page displays the source code and you can execute the mashup -- but be sure you have published the sample services first. The mashup takes an input in the form:
<location>
<city>San Francisco</city>
<state>CA</state>
<zip>94102</zip>
</location>
and uses this to call the Yahoo Map API to get longitude and latitude. It then uses this response to add GEO data to the mashup output using <annotate>.
Hope this helps
Sara, technical writer/jackbe
where can i find code sample for yahoo or google maps by extracting value from webservice and feed as input to yahoo maps??