Help needed on freetextbox

Question

Hi Friends 

I am again in need of the professionals on this form. Thanks for the help in past.
I have a freetextbox,a dropdownlist and a button in my application. when ever user selects a value in dropdownlist and presses button that particular value should be inserted on the cursor location in the freetextbox. if any one have any sample code or any idea as to how to achieve this please reply.

Thanks