How to drilldown in pie chart based on the selection made

Hi , I have a pie chart with different dataservices and its size percentage. I am trying setup drilldown for each of these dataservices. Like if DB2 clicked, it should take me to DB2 database size dashboard, if MSSQL clicked it should take me to MSSQL database size dashboard. Here is the drilldown code i have, I have one drilldown link pattern. I am able to get $click.value$ based on the click made in the dashboard. But the problem is it is in uppercase "DB", "MSSQL" etc. Whereas the actual view id the drilldown has to traverse through is in lowercase like this - /app/sre/mssql_size_details?form.field1.earliest=$earliest$&form.field1.latest=$latest$&earliest=0&latest= How do I convert the $click.value$ to lowercase and then pass it on the url ? Thanks