Set Default value in the dropdownlist using jquery spservice

Question

Hi I have a dataForm webpart in that I inserted a datasource control for one sharepoint list and also inserted a ASP dropdown list .Nexti configured that datasource control to dropdownlist . Now am getting the values from sharepoint list to Dropdownlist in my Dataformwebpart. By selecting any value in dropdown list the data is populated . In dataformwebparti used some filter and sorting to display the data for particular city. But how to set the default value in that drop down list.

 

Ex: In my share point list  i have data like Chennai, Bangalore, Kolkata, Pune

now i want to set default value chennai.

 

please anyone give me the idea.