Implementing CachedRowSet

[surendar prabu]

I am implementing CachedRowSet with CachedRowSetImpl. I am trying to access the columns by their names.
CachedRowSet crs = CachedRowSetImpl();
crs.populate(myresultset);
crs.getString("column1");
crs.getString("column2");

In this case i get an exception message Invalid column name. When i try to use the method getMatchColumnNames() , in that also i am getting an exception.
but when i try to access by column index i am able to do with out any problem. How can i access using column name?? Is there any code i have to add along with this?
Please help me in this

regards,
Surendar Prabu