Hi,
Did you define the web service as shown here:
[WebMethod]
public DataSet GetDataSet(string parameter)
{
// INSERT YOUR WEB SERVICE CODE AND RETURN THE RESULTING DATASET
return null;
}
Did you debug the code of the web service to see what is the value of the string parameter?
What version of Kentico CMS and hotfix are you using?
Best regards,
Michal Legen