How to display selected data from dropdownlist in grid view?

[scotech]

I have a \[code\]dropdownlist\[/code\] in which I want to show different branches of a college.When a user selects one of the value from the \[code\]dropdownlist\[/code\] then the data corresponding to that value has to be displayed in the grid view.For example when a user selects "information technology" from drop-down list box then list of faculty members related to information technology has to be displayed in grid view.